Need advice

So I'm 17, almost 17, and I'm still a virgin. My fiancee is not, however, and up to this point he has respected my wishes to wait until after marriage. However, it's been getting to the point where he drives me crazy, and I want him so badly that I can't think straight. We talked about it and I eventually made up my mind that I didn't want to wait anymore. So in three days, it's going to be our anniversary, and if everything works out, we're planning on having sex then. However, as I'm still a virgin, I don't really know that much about it in the first place. I'm really nervous because I'm afraid that since he's done it before, it won't be good enough for him, and that I'm gonna make a fool of myself. It probably doesn't help that k have very low self-esteem and think very lovely of myself, which makes me nervous about him seeing me. I know he looks es me and he keeps trying to make me see myself the way he sees me, but I just don't believe I'm as beautiful/attractive/sexy as he likes to say I am. Any advice on what to do and how I can get over this fear? Honestly anything would help at this point.