feeling depressed

Ever since becoming pregnant my self esteem has plummeted. Myself and other half have split up, although he says he will support me and baby his idea of "support" is going out every weekend trying to pick up women, spending his money on unnecessary unrelated-to-baby things and I just feel really alone. He doesn't even bother to get in contact with me; but god forbid I should bring this up he tells me he's doing the best he can. I'm living back with parents and I feel like I'm on lockdown or house arrest. Whenever I say I want to go out or do anything that's just about me I get "you need to be saving your money now" I haven't spent money on myself in months. I look awful. I haven't had any energy to even brush my hair or do my makeup. And for me, appearance used to be a big part of who I felt I was. But I can't muster the strength to do anything. There's not even any point anyway, I never go anywhere. I'm trying to keep the pregnancy a secret for as long as possible but you realise as soon as you tell people you can't meet up or go out with them more than twice they just lose interest. I haven't heard from my friends in weeks, my phone never goes off, nobody ever texts me. All I see is my family, occasionally the father of the baby and my work colleagues. All my life involves is going to work and coming home. And from what I've heard when baby arrives it gets even lonlier. Nobody ever says it's going to be like this - I want to be excited for my baby but all I can feel is depressed and like my life is worthless. If I feel like this then how can I be a good role model to my child? Has anybody ever felt like this before or feeling the same? Please. I'm not usually a selfish person I don't want to be this way