Pregnant and alone.

I'm 18 years old, I have a 2 year old and I currently just ended things with my ex he knew i was pregnant he said he was excited he was happy and all this stuff. Then when we broke up he said he wasn't ready I was doing this just to have his kid and I wasn't stopping and then I showed his sister and even she said it was fucked up how he just switched up like that. I don't know what I'm gonna do he already has a kid that he denied to me and I knew all along it was his, his mom even told me... I feel so alone I'm scared to tell my mom I'm scared she's gonna be so mad or disappointed. Idk just someone tell me what I should do.. do i keep it and raise a child by myself or just end it..