Single, but wondering why I am…? ideas?

I feel that I am pretty confident girl. I have traveled by myself, have worked abroad in another country, have my University degree (Sociology), make my own money, drive, volunteered for a bunch of community projects (especially dealing with human rights issues). I take good care of my health (eat well, exercise regularly). I am outgoing person that can carry on a conversation on a lot topics with various age groups, races, nationalities. I have a lot of opinions but do not push them on to other people. I am not especially loud, but am talkative and enjoy talking about a lot of different topics. I have been told I am pretty strong-willed, unusual, tenacious, with a silly unique sense of humor. I have a variety of activities I like to pursue from photography to traveling to cooking. I have always been a fairly independent person with a close group of friends. I think I am pretty good looking as well…I would describe my body shape like Alicia Keys (slighty slimmer), same sort of skin tone, shoulder length dark hair (totally natural, never dyed it). I would describe my style as casual (skinny jeans, funky tops to shorts with plain or funky tees). When I dress up I prefer wearing classy dresses in neutral colors (i.e. black, grey, white) while mixing it up with funky accessories and heals. My celebrity look alike matches are Amanda Pete, Grace Kelley, Mary Kate & Ashley Olsen. I can't seem to understand why I can't attract a guy! I am afraid I am going to be single for the rest of my life. What can I do to attract the right kind of guy? I haven't dated much – only one guy for a span of 3 months. Is their something I can do to attract the right kind of guys?