I've date two similiar men?

I met two of my boyfriends online. One promised to come see me, never did. The second one did, but only once. There are lots of things that are similiar abut them. They both look alike. They said they won't promise anything, but if they really want to do it, they will. They both said when they met me, its the best day of my life. But then why did it both end? They both dumped me. I know i have problems. I say hurtful things, im annoying, i threaten to leave. Now they leave. When the first one dumped me, i was really mad because he said he don't think Im the one for him but I didn't like him as much. I met my 2nd boyfriend, I liked him more but sometimes i dont. he was more tolerant but later left me because I annoyed him. The question is, was my attitude the problem? is that why they both left me? And how could they be so similiar?