How do I start my life over after ending a volatile relationship?

I threw my boyfriend out of the house after cheating on me for last time. I'm 9 months pregnant by my boyfriend of a year and a half. Unfortunately, I realized I have been sharing him with another woman the whole time we have been together. In fact, they were together even before he met me. However, she didn't want a serious relationship with him he wouldn't quit drinking. The last straw was last weekend. I told my bf I wasn't feeling well at all I that I needed him to stay home with me and help me watch my other two children (they are not his). He said he had plans with his cousins and he'll be back around 11pm that night (saturday). I was already fuming, but I gave him the benefit of the doubt. However, when 2am rolled around there was no sign of him. I called his cell phone 4 times and it went str8 to voicemail. So I called his cousins cell phone. However, his cousin's girlfriend answered the phone. I asked her has she seen my boyfriend. She said no that he didn't even come by his house at all that night. When I heard that I wanted to die. Then she told me she's been hearing rumors around town that my boyfriend has been going to this local motel with this woman. His cousins girlfriend told me she could check the motel and see if my boyfriend's car was there. So I told her to go ahead. Several hours later she calls me and tells me not only did she his car, but the other woman. She also took pictures of them walking into the motel kissing and holding hands. She sent the pics to me via cell phone. I was so hurt. I cried my eyes out. Anyway, he came back Sunday morning at 11am. Looking like he was in war movie and reeked of . As soon as he walked in the door I slapped the hell outta him and showed him the pics. We had a screaming match. I told him to don't let the door hit him in the ***. However, I'm due any day now. I have no money., no job, barely even food for my other two children, and my rent is 2 months behind. I had to quit my job because my pregnancy was too difficult. He promised to take care of me and my two children. However, he got laid off around Thanksgiving. I don't know what to do. I'm so scared.