I need advice badly please read..

I have been sleeping with a man on and off for 3 years. . We got pregnant. Our relationship has never been great but it's been real. Lately I am so sick and tired of arguing of what I meant to say and what I mean.. why I don't like things and why I don't think it's ok to talk to a woman you slept with.. I'm so exhausted that I just hang up and or end the relationship. So now we are pregnant and I'm ready to throw the towel in.. is this what's right.. just walk away.. I can't keep defending myself or begging him for his attention and commitment.