Love comes in many shapes and sizes. The one girl I have ever loved was not what I would call my "type" by any means. At least not at the time. She also thought she was ugly, never wore make-up, etc etc etc... She may not have been my type, but she sure turned into it. I find her the most beautiful girl in the world whether she or anyone else thought so or not. She was the one always saying she didn't deserve me, etc etc etc... Much like you are saying here.

Guess who broke who's heart? SHE left ME.

It doesn't matter who he has dated in the past. Love has no "preference". It's hard to trust people, but you have got to try if you really love this person.