advice please

I'm super new to this but I like how the conversations work and everything.

But here's my dilemma:

So I'm a 22-year-old virgin, which seems to be really special where I am for some reason. Every guy who has ever hit on me wanted sex; a current guy I'm "talking" with is 24 and i knew him personally. We went to the same university before he left. I've known him since my freshman year (I'm a graduate now).  I've always shown hints that I've liked him, but he never really showed me that same attention back, from what I could see. Since he's been gone, we've talked on Facebook and now through text. I've sent him nudes when he asked. He keeps saying he wants to see me (even before he started asking for pictures). 

It makes me nervous now because he has the means to come and see me. As excited as I was, I don't know if I'm ready to have sex, but I want to try other things. Should I continue to give him my time or ignore him? I always wanted to loose my virginity to someone I'd be with for a while and because I don't know his motives as clear, it makes me nervous. 

I hope all of this makes sense.