How can I help my girlfriend's insecurities?

My girlfriend whom I’ve known for years, has recently been insecure about her weight. She is still pretty thin and really attractive, but the weight issue along with a trust issue is creating a huge gap.

I tell her she is beautiful almost every day and a lot of times she will reply “No, I’m NOT!” and get increasingly mad as I try to re-assure her that she is very pretty. It gets to the point she doesn’t talk to me for hours because she is pissed. Sometimes her mood does a complete 180 because of this too. She gets so mad about it she starts cussing and yelling but I know I shouldn’t take her anger personally. When she gets mad (or as she calls it “upset” because it is a lot different than mad and men don’t understand because they have limited emotions..so I’m told) and doesn’t talk to me for hours I then try to tell her how important it is to talk to each other and that makes her more mad and I get a longer silent treatment. Eventually after one of us leaves from anger I will text and apologize for making her angry…and thus starts the texting argument that leads to me being a horrible person somehow.

Her not believing me when I say she is pretty is partly a trust issue I think. She doesn’t believe a lot of things I say though I have never done anything to make her not trust me. She does have a bad history of guys doing things to make her pretty much hate the male species, but I can only take so much..as I have told her.

Anyway, aside from me constantly re-assuring her that she is fantastic and great looking…cuddling and giving her hugs (which she also doesn’t like because I’m “putting my hands on her fat”)…and telling her that I wouldn’t lie to her (another lie by the way)…what can I do?

I probably shouldn’t have written this right after a texting argument. I do love her a lot and she is really great. If she had more self confidence and trusted me there wouldn’t be any arguments. I can’t think of anything I haven’t tried so any help is appreciated.