Is it a good idea to try and run away. NEED ADVICE?

I'll try not to go into to much detail. My in laws are ling, cheating, and stealing no good for nothings. I'm 23 weeks pregnant and for the life of me it seems I can't get my husband to care more about me and our baby then his crazy family. He knows he's doing it but he's either to cowardly or to brainwashed to change. Tonight I said I am so tired of it I feel like taking my own life and he got snappy at me for it. He's a great man and nothing like his family, but it's always them over me. I can't do it anymore. I figure maybe if I leave him for a while he will change. Any advice would be greatly appreciated.