Being left 7 months pregnant

I was left pregnant at two months with very minimal communication. It hurts but very much. At first he reached out to me promised to be there and support me financially all while having casual sex. I found out he was still sleeping with his ex he disappeared. I reached out and he apologized and for a week he was asking how I was boom I get a weird message ask him about it and boom disappears. Weeks passed and once more I reached out because I’m now 7 months pregnant and wanted to know where the help was he promised and he apologized and sent me money. The other night he wanted to speak and we did. I stupidly slept with him. Stupid I know !!!! I’m very close to his brothers girlfriend who told me he’s dating his boss and he’s doing really well financially. It’s my fault I stupidly fell for it I need some advice it’s been 5 days and I’m in a dark place. My mind is going and I feel so used. Like why sleep with me when your in a relationship. I noticed yesterday he also deactivated fb where we have communication. He told me he’d send my maternity pics money and gone... ugh I’m so upset I was doing so great. Please nothing negative I’ve been going through a lot. We were in a relationship for a year and his ex knew about us she started a rumor he believed and that’s how it went. Just for clarification.