I understand your feelings and have struggled with them at times myself.
That said...snap out of it! *friendly slap*
I don't even need to see your picture. "Too fat"? Too fat for what? To be loved and for a partner to find you attractive? Well, sure, there will be some people out there who are only attracted to a thinner body type, but there will also be plenty attracted to how you are now. And apparently this guy is one of them.
I know it's hard to grasp for ourselves and easier to say to others, but the truth is perfection isn't needed. Being yourself and confident in yourself and open to others is what's most attractive. Some extra weight does not render you undesirable to all partners, but it may to yourself. And if it does, that's what you've gotta work on. Understand that you're a catch just as you are.