You need to leave him to protect yourself and your baby. Now. I know you think you love him, I know you think that, somewhere down the line, there'll be a switch that will change him and make him nicer, calmer, not abusive to you. I know you think he loves you and that his anger is because of other reasons.
None of these things are true.
When I was 16, I was in a relationship with a boy. It started out brilliantly and I was completely in love with him. Things soured slowly. First it was petty arguments, then he started commenting on my clothes, saying they were too revealing and that I should dress more modestly. Then he started separating me from family and friends. Alongside all of this, the arguments got bigger, I was a slag, a slut, a bitch. He started hurting me, little shoves at first, then bigger pushes onto the bed. Then harder into a door or a wall. Then he started kicking me, punching me, choking me.
In the midst of all of this, I got pregnant and had my son. One day, while I had my baby in my arms my partner held a knife to my throat. It was at that moment I woke up. I realised that he wouldn't change, he didn't love me. He wanted to control me and abuse me and that my beautiful baby would grow up thinking that this was normal, or worse, be abused by this bully himself. I calmed down, got the knife away from me and boded my time until he went out to buy cigarettes. As soon as he left I grabbed nappies and ran. I never looked back.
Almost twenty years later, I am married to a man who loves me. Yes, we've had the odd disagreement over the years but I can honestly say he has never hurt me, never swore at me or called me horrible names. We have more children together and he loves my first one like his own. I have never seen my ex since the day I left but I have heard that he's been in and out of prison and badly abused other women.
They don't change. It is your duty to protect your son and you must. You will find happiness one day with a man who loves and deserves you, a man who respects you and wouldn't dream of hurting you.
Please, please take what I've said on board and get out of there. Call the police, family, friends, women's aid and anyone else you can think of to help but do not let this man ruin your life.