Oh Blue, I certainly understand what you are saying. I, myself, used to believe there is someone for everyone. Now, however, I believe that is not realistic. Even if it is true, relationships take lots and lots of hard work. I spent plenty of time and energy looking for the "right one" and ended up marrying the first one that was nice to me. I married after I gave up on my search. Please do not do that. I think maybe you should give your relationships a fair chance before you shoot them down. You could be throwing away a wonderful relationship and not know it. Just relax and let whatever will happen, happen. Don't worry about if there is something better. Focus on the relationship and if it is not right you will know. Let things flow naturally. Allow yourself to feel in relationships and stop running. You haven't slowed down long enough from your run to enjoy a relationship. I say all this because I am guilty of all the same feelings and thoughts. Even after marriage I continue to run. Please, just allow someone to love you. I know it is merely impossible to believe someone could but give people the benefit of the doubt. That is what I try to do. I don't know if I helped or not. I am just going by my experiences.
P.S. When you do give a relationship a chance, please make sure he is good to you.