I cannot believe I'm going through so much!!

Im currently 5 months pregnant and I'm soooo stressed. I've been stressed since day one. I'm only 20 yrs old and I feel like I'm in this all by myself. I found out I was pregnant once I cut things off with my ex and he has a girlfriend. He's denied my child but now wants me to give him his last name. He isn't involved at all really and I'm in desperate need of that support and backbone. He sneaks behind his girlfriend pretty much which I feel is unfair to me. His family and friends check on me more than he does. He text from time to time but I don't feel that's enough. I think he should b come around and experience this pregnancy with me so he's  able to bond with our child just as I do ..I'm so lost and I feel alone