This sounds very familiar to me. You sound as though you're in a lot of pain.
I tend to think that sometimes recognising that a relationship is over and actually 'giving up' can take more strength then putting up with a miserable life. You have to decide for yourself where you go from here, but I can tell you from experience that having a partner who derides your attempts to talk about your feelings, who devalues your opinions, and who refuses to take responsibility for their own actions will eventually chip away at you until you feel like a shell of your former self. It's actually a form of abuse. People who cannot admit fault or even acknowledge that things can look different, and not wrong, through someone else's eyes don't change. Why would they? They're not wrong, it's everyone else...
I've been through something very similar to you and I think it's going to take me a long time to recover. If someone makes you feel worthless for long enough then you start to believe that it's true. Your son needs to learn from the start how to treat women and lovers with respect. He needs a happy and healthy mummy. Feel free to PM me if you'd like.
BTW, I don't mean to imply that you're weak if you decide to stay. Just responding to your statement about giving up. Only you know what's best for you and your son. Perhaps counselling on your own will help you, if for no other reason then to vent and to have your feelings validated. Best of luck to you.