Not Too Close Please

I have had trust issues all my life and I think it had alot to do with all the bullying I got in school. I think it was just because I was the quiet my peers and some teachers found because I didn't speak they would for me and I had rumors everywhere about me, I remember specifically how isolated I felt, I wouldn't wish that kind of punishment in anyone. Ever since then my self esteem has trickled itself down into a little puddle and I find it easier to put on a false façade for others to see.

But now I'm older I feel trusting others should be alot easier and I assumed with time my life would just correct itself but unfortunately I was wrong. What am I meant to do when I guy I like actually likes me back but I can tell he is utterly confused about my own intentions. I've never really been in this kind of position because I generally never let anyone get through my little barrier, and since now it hasn't really been a massive problem but I really like this guy, how do I let him in, and how do I know he won't hurt me?