Why do I find being intimate with him so hard?

I've been with my boyfriend for nearly three months now. He's touched me down there quite a lot, and he's done other stuff - and I feel completely comfortable with him doing things to me. But when it comes to touching him I just freak out, and it's at the point now where it's stopping our relationship going to the next level. We both want to have sex, but I'm pretty sure he's waiting for me to initiate it by doing stuff to him to let him know it's ok. The even crazier thing is, he's a virgin, and I'm not. So of course he is actually really nervous and doesn't know what he's doing, so he's expecting me to help him and guide him in some way, and he's expecting me to be the dominant one, which is as it should be really. But even though I've had more experience than him I still have only been with one person so I really don't know much, and even with that one person I wasn't the dominant one - he always took the lead so I'm really not used to the spotlight being on me so to be frank this is my worst nightmare! I really really care about this guy, and I want to please him... But I don't know I get it in my head that I'm just going to take the risk and do it but when the opportunity actually comes the thought of it just terrifies me - like he'll be expecting me to know what I'm doing and realise I don't have a clue, or he'll react badly to me even touching him there anyway or just me doing something wrong, getting really embarrassed and everything becoming really awkward. Even with sex - I'm not scared of having sex with him, but I am scared of going on top or just being the one in charge, not because I'm lazy it is just a genuine confidence issue I have. He hasn't asked me to do anything or pressured me at all but it really does feel like he's giving me a whole lot and I'm not giving much back and it's making me feel really bad. The whole situation just scares me so much, but I really want to go further with him so advice on how I can get over how i feel about this or how I can go about the whole thing would be very much appreciated!