Does this sound like genuine veganism or more like veganism is a diet for me?

Well, I've been vegan on and off for several years now. But lately, I've started to notice myself thinking that if I don't go vegan, I'll eat a lot of fast food, and to avoid that, I shouldn't continue vegan. And in the background, I have this thought that I'll get fat from fast food. I generally try to be vegan for ethical, environmental, and other reasons,So initially I think that my intentions are sincere, but I'm starting to think that ED has found benefits in my veganism, because on veganism I somehow eat less, now I have no appetite and it worries me, but somewhere inside I like it