Should I use hypnosis to forget him? I'm sick of crying over him. :'(?

First of all, there is no psychologist that would be able to completely erase your memories, so unfortunatly, that is something that only exists in televsiion and movies. Secondly, in the long run, I think you will be better off having this experience (though I know now it does not seem that way). Sometimes from really bad relationship we learn more how to avoid those relationships in the future. So far, it seems like you now know that he does not deserve you, which is already a very powerful lesson. It is cliche, but time will heal (maybe not completely, but it will get better)