Abusive husband is giving me the silent treatment for 2 weeks now, Why do I let him get to me?

I am in an abusive marriage for 13 years now and we have 2 kids. He calls me names, hollers to the top of his lungs in my face and tells me he doesn't care about me. He goes back in forth from supposedly loving me being nice to treating me badly and giving me the silent treatment for weeks until I talk to him and apologize. I am not apologizing this time for something I didn't do and I am so sad and depressed because I wish I had a happy normal life. I don't know how to move on because he's all I know. He looks for other women online and tells me that any woman is better than me and that he wants to try a white woman because they are more docile than black/spanish women. I would hate to see him with someone else and I am left to raise 2 kids and feel like the I am discarded for someone he feels is better. i think he'll treat another woman better than me. I don't know what to do anymore and how to move on in my life so I can be happy. My therapy is helping just a little but not enough.