I feel so alone and depressed

My baby's father recently got into a new relationship and I'm having a hard time dealing with it. I try to keep in contact with him because I am having his child and of course I love him but sometimes he won't text me or if I text him he won't reply he told me don't call because his girlfriend knows my number. It really hurts like how could he not care about me anymore that quick and how could he not care about his child. I've been so stressed sometimes I can't sleep or eat and I know ultimately my child is the one suffering. I just don't know what to do and I have no one to talk too.