It’s very honourable that you want your child to have both parents together however if your relationship with your partner is beyond repair which is what it seems the case for you. My mum did the same thing, for years she was fighting with my father and then pushing me and my sister to have a relationship with his cuz he is our father and that’s the right thing to do. We hated both my mother and my father as we were miserable with them. My question is, will your child be worse with you and the partner fighting all the time or you separated?
My best advice is to plan your escape and get your ducks in a row before you leave. Finances, childcare, savings, living arrangements, solicitor etc. Are you married? Do you have a joint mortage?
Yes it’s normal. I’ve known people who’ve also felt like this in their relationship. My only advice is you need to be happy and think about yourself, if you’re this unhappy don’t feel guilty. I was bought up with my parents separated and it didn’t affect me. You need to be happy also for your child’s sake! Do what’s best for you, your little boy and your mental health❤️