How Can I Stop Myself From Choosing The Same Guys?

I'm not very fortunate when it comes to relationships or dating in general. I've read many articles that said I'm probably the problem. However, I find that the changes I try to make within myself make no difference with the end result. I don't have a low self esteem or struggle with loving myself. I do enjoy my own company. But I find that whenever I meet a guy, he initially is interested me (approaches me first, asks for my number, contacts me etc.) and then disappears. They all seem to come to this realization that they really aren't ready to be with someone and I guess I'm this big reality check...which is fine but it always leaves me hanging. I'm not clingy at all and will gladly give someone his space if he needs it...I just want them to communicate that to me and they never do they just...disappear. How do I avoid getting involved with people who think they want a relationship, then decide they don't want one shortly after?