Husband didn't trust his wife

I am married for 16 years with 5 children. I made a mistake, and I don't think it is, when we were on our first year of marriage we bought a phone, there's this guy a lot younger than me sent a wrong text to our phone from there we've become friends, (his from the opposite side of the country) he was sick and thought being of friend to this guy will help him fight for his illnesses. But it was just that friendship text and nothing else. My husband got mad about it so I stopped texting and even change my number. For that 16 years of marriage, I've been faithful to him, never did thought of having any other man than my husband. I love him. I focused on working to help him financed our living. I never stopped working, doing my obligation as a mother to our children and wife to him. I am working as Administrative Assistant and I am not staying long with companies because if there are guys in work he's thinking I am flirting with them, he even accused me that our youngest child is not his. I resigned and have my luck in online homebased job last 2012, but nothings changed, it became worst, more stressful, he always accused me of cheating. Every time I am having a chat with my co workers, his eyes were on my laptop, every time he got home from work, he checked my phone my FB messenger, emails, everything. He asked if I went out of the house. If I needed to go out I need to ask permission, and if he permits, I need to bring with me my kids or nephew. He should know what time I arrived home. He don't want me to go out with friends, chat with friends. One time, he got home from work about 1:00 am and he saw me on the living room working on my laptop, he told me he saw a guy in front of the first gate, we have 3 gates because we leave in a compound were the first gate is about 300mtrs away from our door, he said the guy was texting, I asked if he knew that guy, he said no, I then told him, the guy might be drunk. he then asked for my phone and entered our room, he said he smell a beer odor inside, I said that odor came from the kitchen in which our room is in front of the kitchen. From that conversation, I know he is accusing me again. He didn't talk to me since then, he was always that way when he was accusing me of cheating. I am so tired with this, I was always been faithful to him, I am busy with my work, I didn't even have the time to take care of myself. I have 2 full time jobs, I am working almost 16 hours a day including Sundays. I am so tired physically and mentally. He didn't trust me and he told me that, he even said I am a maniac, a whore, I already heard all the bad things from his mouth. I felt abused mentally. It really hurts me a lot every time he tells me those words. I always asked forgiveness when I texted that guy 15 years ago, he forgives me but every time he accused me he always brought that up and again I asked forgiveness for him to stop. I also told him I am not going to ask forgiveness with his accusation because I didn't do that. In our 16 years of marriage, I never heard him say sorry for all this things. Many times I am thinking of leaving him, but I was afraid for my children. I am against broken family, I wanted to have a peaceful Christ centered family. I am earning much than him ever since, I spent all my earnings to them, I even forgot mine just to give them comfortable life. Please I need an advice.