22 weeks pregnant getting married in 20 days but found out i was being cheated on

The moment I knew I was pregnant was a shocking moment for me and my partner, I was crying so bad because I felt I'm not ready for this and I know that it will take a lot of sacrifice. My partner offered an option that I will take an abortion it doesn't really coincide with my morale so I took all the courage to face everything I have and keep the child instead, My family was disappointed as I was also to myself... I live in Ireland taking voluntary work for people with disabilities and was afraid since my visa is going to expire that means for me and the baby to be away from its father. Little by little we found our way to address the problems we had. we tried and given our best to do everything we can to be together as a family, but along the way of our relationship we stumble upon people that question our relationship he is a very jealous person, at first in our relationship his was always interfering with my privacy and always find a reason to question my loyalty. I understand how he became like this as he also struggled with his previous relationship since he mentioned to me that the woman was the one cheating on him.So he became too afraid that it will happen to him again. One day a woman ask me through Facebook if I am his gf and she told me she got pregnant with him and lost the baby . he sent her sex videos and schockingly ( I was the person he was taking the video and I didn't know he was doing that to me). When I try to ask him and told him it wasn't okey with me he defended I make so many drama about it.

And then the woman warned me about him that he is a cheater and a liar. Then he starts to make issues again about me trying to find and make me look like I was the one cheating. Now I'm on my 22 weeks with the baby. And getting married in 20 days I found that he was sending dick pictures to other woman trying to have sex convo...this is not the only time I caught him, once in our relationship he had sex with other woman because he was angry with me.. And make an excuse I was cheating on him too. I know to myself there is good in him but I don't want to be treated this way. I know to myself I don't need him, but my child needs its father, I know to myself I don't want to be lied to or cheated on, but why I always seek good in people and try to defend them rather than rejecting them because of their mistakes.. Why is it so hard for me to be disappointed and vengeful to other person when in fact I have a good reason to be that way but act as if "its not okey with me, but find a way to change your mistakes." I don't want to tolerate people like him I've seen this already to my dad but my mum always forgive him and obey him. I don't want to be a hater nor bad to others but I also don't want to be taken for granted and tolerate cheating and lying as if its okey.