Why do people hate me for being pretty? NO joke?

not trying to boast or be snotty, but i used to have very low self esteem so i worked on myself: therapy, exercise, make over, new clothes, and gained confidence and better social skills. Problem is, I think people assume I am a totally different person from who I am. I still am the nice, sweet, kinda shy and somewhat conservative girl i used tko be but more assertive. This doesn't seem to be helping my love life! Guys always stare but never approach nor ask me out! All they seem to want from me is sex. I'm tired of being "hot" and not taken seriously. I am smart and nice and loyal and affectionate and would be a great g/f, but guys just lust after me and date the other girls. I don't get it! How can I get them to want to GET TO KNOW ME TOO even if I "look hot"? One guy I liked (who everyone else thought was not "good enough for me" ended up telling me he found me very attractive, but wasn't ready to date...He now has a crush on someone else (plain looking girl into computers) and I wonder where did I go wrong? I'm a virgin, so not a "slut". I notice he hangs out with her and does things with her he never did with me, which hurts b/c I really liked him and he just stringed me along, probably to get sex! How do I stop this???? HELP