I can't find my ego...

My boyfriend has a problem....or that's what I think it is. He's a frequent masterbater. The problem is that he chooses to masterbate than to have sex with me. We have a two month old and the time we have alone does not come often. I noticed that when I was pregnant, he would just go into the other room to jack off. He wouldn't even try to seduce me. Now, when I ask for sex he'll say okay and than end up doing himself. I already feel unattractive, but this brings it to another level. I feel hurt, sad, confused, and unloved. I can't sleep because I'm up trying to finally understand and it just brings me to tears. Am I really not good enough for him anymore? Please help me.