My boyfriend wants to have sex. He's 18. It's understandable.

i'm 16 (less than two years younger). I'm not 110% sure i'm mentally mature and strong enough to..... I want to.....but i'm scared I won't be able to cope.....

so we've agreed to build up to it........ yet he's so respectful of my body and my wishes that he is waiting for me to make the first move....... but i don't know what to do. I'm too shy..... to frightened of doing the wrong thing and going too far but not being able to stop.....

what do i do?