Should I text and apologise or not?

SORRY FOR THE LONG POST, JUST WANTED YOU TO GET THE FULL STORY:
I was recently in a strictly FWB's relationship with a guy but one night he had invited me over to a party where he was at to basically come sleep with him and i decided to go. When i was at the party this other drunk just came up to me and kissed me which for some reason made my FWB really angry. He began to call me a whore and told me i was stupid in front of everyone at this party as he said I must have done something to make the guy think it is okay to kiss me. ( I did not even see why this would upset him too as at the party he did not even say a word to me, he came and said Hi and then disappeared for the rest of the evening until he found out this guy kissed me). A little upset and embarrassed I had left the party but my FWB came with me when I walked out of the door and apologised for what he had said and we just left it at that.

The next day I had received a text from one of his friends that I was speaking with at the party (as he wasn't speaking with me) claiming he got my number from my FWB and he wanted to hang out as he thought I was nice. I told him I thought it was a bad idea as i was sleeping with his friend and he said he didn't care as he gave him my number. My FWB then sent me a text encouraging me to hang out with and speak with his friend that was texting me, so I did as my FWB kind of made it very clear to me that it did not matter (he told me this himself through messages).

One night my FWB invited me over again to a little get together at his house and I decided to go. His friend I had been texting was also there. At my FWB's house he did not even speak with me or even say Hi to me ( I even took a call while there as I felt so uncomfortable being there). At this point his friend that was texting me saw how awkward the situation was so he came over to me, offered me a drink and started speaking with me. After a few drinks with this guy another girl had arrived. I found out that she was invited by my FWB for him to hang out with. As soon as she walked in he started speaking with her and was rubbing her arm and all as if they were flirting and stuff so i just ignored it and continued speaking with this other guy but after about an hour or so he had disappeared with this other girl for about over an hour or so leaving me with his friend.

His friend and i just let them be and continued to drink together but after a few drinks one thing led to another and we slept together (this FWB was still gone with this other girl) but of course he found out about after it had happened and went crazy. He started calling me names and told me to leave their house (which I did) but again i did not understand why as he did not seem interested in having me there or as if he cared if I was actually there or not.

After this incident took place I decided to just leave this guy as he really confused me all of the time and really hurt me what he said (please know I absolutely hate fighting and conflict and I never said anything back when he shouted at me before, just stood there, would apologise and leave).

After a few months went by he sent me a few texts asking to hang out and i either said no or just ignored him. I also told him I think we should stop texting as I wasn't going to see him again (I sent that text when he texted me one night from a party telling me to come over but little did he know that I had a friend at that party and she called me earlier that evening saying he was speaking badly about me and stuff) but after about 3 months I got a bit drunk and sent everyone on my Snapchat story a snap.

He responded to my snap and started sending me messages on snapchat which led me to calling him. He told me to come over so I went over to his place and we spoke for a bit. While speaking he mentioned the last party they had that he invited me to and asked why I didn't attend which led me to bring up a discussion with him about a conversation I had with a friend about that party (she attended the party). Basically my friend said at that party he was speaking badly of me and was being mean about me so I just said my friend said you were saying stuff and i just want to know why and what did you say?

He then literally went crazy and told me to not speak with him again and to leave his house and started calling me names again. That night I didn't just stand there as I was so angry he couldn't be civil and would just lash out at me like that. What I had said in return was very mean and hurtful. Like i have never been so rude to someone in my life before and it made me feel terrible. I feel as if fighting back was actually unnecessary and i did not have to say the things I did but anyways after we fought he told me he was deleting me off of everything and never wanted to see me again which just infuriated me even more.

I barged out of his room where one of his friends were doing some work and I walked over and started kissing him (I was just so angry i wanted to get back at him for being so rude to me) but soon after the guy started wanting to do more but we stopped it from getting that far and i decided to leave as I was not going to take it that far (Although we were almost undressed and all, I did not sleep with him.)

The next day this guy and his friends I used to speak with had deleted me off of all social media or anything I had them on. This clearly shows that my "FWB" clearly has no interest in ever speaking with me or seeing me again. I do, however, feel absolutely terrible for the things I had said and me kissing his friend. What I did was completely out of line even given the circumstances and I feel absolutely terrible for it and that is why I want to know if I should send a text apologising. I know he does not care and wishes to never speak with me but I really feel I owe it to him to at least apologise for my actions and my words so he knows I do not want to hurt him but I am afraid he will see it as me being desperate or might be angry if I send a text (who knows he might have blocked my number) but I just really feel what I did was wrong and I have to apologise for it but I am not sure if I should send the text and apologise or not?
Should I send it or not?