I have a son supposedly due next week and i’m not excited at all, is that bad?

Im a 20 year old male and is having my first child next week. When I first found out I was scared and knew from the jump I wasn’t ready nor wanted a baby right now, and to add it was with somebody I only had sex with and knew nothing about. Yes i understand i fucked up with nutting in somebody like that but the plan b i bought didn’t work and she was 100% against abortions. So it was a bunch of arguing and going weeks maybe months without talking to each other. I also told her that i wanted a dna test and she immediately got defensive and was/is still refusing to get one which makes me even more not excited cause what if he isn’t my son? But I plan on putting myself on child support so wouldn’t she have to get one? Anyway, so one day I ended up doing shrooms and came to my senses that this is a blessing and it can really help me become a man. But for some reason I cant get over the fact that this is the lady I had to have a baby with. I really don’t wanna go into detail with exactly why but I made a promise to myself not to let this affect me and my son’s relationship. I really am grateful for him, but for some reason I just don’t feel it.