I'm so torn

I'm sorry to make this so long but I really have no one to turn to. I'm 18 years old and I'm about to start my senior year of high school. I'm engaged and my fiance has been saving up so we could buy our first house once I graduate. He has a full time Job making 18 an hour and I was just hired 3 days ago part time making 10.40 an hour. Today I took a pregnancy test and I'm 2-3 weeks pregnant. We currently live with his father and step mom who told us when I moved in if I got pregnant we would have to leave. He keeps telling me were not ready for a baby, it would ruin our life and I need to get an abortion. I can't stop crying because to me if feels like I'm going to have to kill my child. I've expressed this to him and he keeps telling me it's not a child yet. I'm very superstitious and I asked my father who passed away when I was 4 to play our song when I changed the Pandora station if I'm supposed to keep it and our song was the first one to play. I can't help but think getting an abortion would be the worst thing for me but at the same time I'm so scared of what will happen if I dont. I have depression and anxiety. We don't have a house, my fiance and I both have 2 door cars, he also has a bike and a truck so are car insurance is high and he's still making payments on his car . My fiance wants a 2000 sqft house and anytime we talk to our realtor the houses we like are too much with taxes. And even if we did get a house we'd be living off of basically nothing. I don't have any family that would be willing to help and my fiances parents aren't stacked with money either nor do I feel like they would be willing to help considering they would kick us out. I'm looking at this as a miracle and I feel like my fiance is looking at it as a nightmare. He even called his best friend who is getting a divorce with his wife and has twin boys and he said to get an abortion. Obviously I'd give birth sometime in March I think so I'd have to finish my senior year leaving my newborn with someone else. Plus I'm going to a new school so I know I'd be the person everyone would be talking about. I just need support and my fiance is all over the place so I can't expect it from him rightnow. I've tried telling him there are ways to get support financially and things don't have to be bought new but I feel like that is not doing anything for him. Please. I need support, success, suggestions, anything....