Confused

I feel like at 17 I have already let myself go and I already know how I will be as an adult in a relationship. I talk to some guy we have been friends for 2.5 years and we have done things and I feel like I am asexual or maybe because I am a teenager I don't want to let my mom down by ending up pregnant. I have gotten on birth control made sure condoms don't break make sure he wipes his hands before touching me and it seems like I am always scared. This is my first month in birth control and even tho we didn't really do anything and I try to be cautious I am still so scared. I no longer know what to do. I have been taught about sex I know how it works I'm not stupid. I know this guy cares about me and I want these things with him I want to be okay to have sex with him but I feel like I'm going to have to tell him that we can't do anything anymore because I am scared and he really likes sex.  I'm really at a loss. I don't want to be a ppl pleaser but I don't want to keep stressing myself. ( if I put this in the wrong topic group don't act like 5 yo about it)