What should I do about my boyfriend?

I love my boyfriend very much and I eventually want to get married and start a family with him, but he has 4 kids by 4 women and he's been traumatized by their immaturity and drama (even though he doesn't talk with any of them and we even raise his 4th child together because his mom is a deadbeat). I always tell him and proved to him and he has acknowledged that I am different these other "street rats". Every time even make a simple comment about " baby mamas" on the Maury show (for example) he goes into severe PTSD mode and rages on about his past and why it is horrible being a father, baby mama drama, etc,. Even though he's not addressing me I feel horrible about myself. I tried talking with him but he just interrupts me and says what he wants to say and I rarely finish half of a sentence. I don't know how to communicate with him anymore. He talks down to me and yells at me for the silliest reasons and makes me feel like dirt. I feel like I want to give it one last try and if all else fails I will leave. Advice please?