I want to marry him but i am afraid

Dear peeps,
I couldnt be more honest. Pls try to see both the sides and advice. If u think i am wrong, pls correct me.
I started childhood relationship when i was in class 9 with guy X. I come from a abusive and domestic violent family background n was neglected. The last thing i could accept was an abusive partner. He was really nice and loving initially for several years but we were always on phone hardly met for a while during vacations. Then after 3 years i decided to move to his city for my Grad so we could spend more time together. He was not very happy about it. He was worried he might have to spend more money and time on me while he himself was a student n preparing for a difficult professionals exam. I agree he was not wrong to feel that way but i tried my best to support him understand n be helpful. Even though i also accept i was not very mature at times and was needy for his presence attention and love while he was busy with studies or family. He used to go for long term to his hometown while i was waiting. At times i was jealous he spent time with other female friends but not me while i was alone in his city n came there for him. He tried to spent reasonable time with me, but i was not satisfied for long periods. Many guys came in my life as friends and tried to have relation with me asking gently but i refused so i could be loyal to my guy. However once owing to my needy and immature nature at that age I fell for a married man who was in my classes. Even though i knew i was doing wrong i could not resist him and it kept going for few months. However my bf found out and was broke. He was suicidal, slapped me and tried to kill himself. I apologized and comforted him. We both were in state of madness for a while but it all went so bad i decided to leave the city and went to another city for solace and further studies and post grad. I broke up with both. Howver my bf was not at any mistake so when he tried to reach me usually to cry and ask me why i did that to him, only to help him feel better we stayed in touch. Eventually he realised it was just my immaturity and he forgave me. On his persistence we continued the relationship again on distance. For 3.5 years we were on long distance while he was still preparing and failing attempts at his exam, i finished my PG n moved back to his city. This time was not same. He was a different man, he was secretive, but still loving and caring. If i tried to find out or if something surfaced about him that showed he is lying to me about some situation or flirting with some girl. He would try to hide and lie more. I too had a digging nature which flared up the fights and we reached a point where relation got abusive physically emotionally and verbally. We moved to live in together as it seemed may be distance is the cause of problems. But that didnt help we had cycles of fights and love making in span of week. He had been physically abusive at times. Once when i found out he was flirting with a girl and was arguing with him. Once or twice it was because he was not happy with my family or my behaviour with his family. He always felt i am not loving and respectful towards his family. Although i never did anything to make him feel that way. Infact even he never felt that way himself only when his parents complained i dont call him enough or dont reapect them he started complaining. One thing which we initially enjoyed was drinking and eating together on weekends. Suddenly i didnt realize when that turned into a nightmare when after drinking he became contrary to loving and caring, he started complaining and fighting and crying for stupid reasons. Then i decided i dont want to waste more time with him and filed for my PR for another country where my siblings were settled so i could be close to them. He helped me thru the process but was extremely unhappy that i was going away. He too wanted to leave his city but being only son he was not sure if he could come to another country. I persuaded i will call him as soon as i get job. His family was also unhappy about my decision and instead wanted me to marry him and then leave with him. But i was afraid with his controlling nature he might not let me go. I was afraid of marrying him and honestly sometimes i wished and felt i should get a better guy even tho i love him he never treated me exceptionally nice or giving towards me. I even shared finances and bills, paid him rent when staying live in in his own home as it was belong to his parents he said not him. But it was ok for me. I only felt that i make him feel always so special he only tried doing that when he too knew has been too much to accept. Well i moved to another country against his will. We both cried a little. I was hapoy to move close to my siblings and family and felt more secure. He was very unhappy and blamed and complained. He stopped talking to me. I got job in a month time and requested his family and him for marriage. But they all were not talking to me nicely for going away against their wish. I wanted him to move with me to new country which was good for both of our career and future. Initially he didnt agree. We talked lesser every month. In 6 months we were almost not talking. He never initiated or talked unless i called thruout the time. I apologized and requested for marriage. But no avail. Then i met a guy at my work whi was really helpful and helped me thru my work nd sustaining job extremely as i was hired for a role i didnt had much knowledge. Later i learned and got stable but till then he helped me a lot with sustaining my job. While my personal life was in shambles he became very good friend too and we started going on friday drinks. Until one unfortunate day when friendship went beyond. We started going out more and fell in love. To my bad luck he was also married and i knew that since day one. Infact while friends he also told me he likes his wife as they are very good friends too. So i knew he wont leave her for me. Even though he said once for a while that he is mad about me and wants to leave her. But that lasted only till he realised its too much of a hassle. Moreover his wife is a good person so y should she be penalised. So he apologized and told me he cant break his marriage but could do anything else for me so i could digest this as easy as possible. I asked him to continue relationship with me till i can come to terms with this fact and stop feeling hurt and love for him. Also i told him to give me proof that he only lives with his wife as a friend and not having any physical and emotional bonding. He agreed. And frequently gave me audio proofs proving he was loyal to me even if he could not give me 100% partnership. If this was not something i needed. His treatment made me feel much better about my situation and i feel blessed he was not like any cheater. Also i came to terms with the fact that i have to move on. Meanwhile i was in relation with this married guy from work, my bf returned and asked to marry me apologizing his abusive behaviour in past. He says he still loves me although i only feel sympathy for him no love. He says he misses me too much and difficult to live away from me. I dont know how now. When i wanted to marry he said he no. And now i am so scared. If i accept him and he found out that i had this relation in mid while we were away i am afraid his abusive side might kick up again and he will not love me anymore. I have reached a age when marriage is mandatory. Infact from the country and society i come, i am too late already. I want to get married and setlle down. But too much in mess state of mind. I love this married guy from work extremely and so difficult to leave him and move on. Even tho i dont have a choice. My bf wants to marry me is sorry for his mistakes but i dont feel love for him any more just a soft corner and more i am afraid of his reaction and abusive tendencies but since i know him since 15 years i feel may be i can live with him for rest of my life rather than marrying a complete stranger in arrange marriage. Pls help me. Pls advice. If refuse my bf now for marriage anyways we both will have to marry someone else n settle as we both have reachdd high time in life to marry now. I am also afraid of starting over new relationship while my love n loyalties have changed n still belong to someone. Pls guide me.