I really believe that attempting to limit oneself leads to splurges and binges. I came close to having (or really had, probably) an (over)eating disorder as a teen ... when I said "f**k it, I'm eating what I want when I want, and if I gain 100 pounds, so be it," then I became -- without ever trying or thinking about it -- quite slender. Weird psychological stuff -- I was "pigging out" in my own mind (and not even making healthy choices, we're talking pasta with alfredo on a regular basis here), but when I look back it seems in reality that I was eating quite reasonably. (At least calorie-wise.) Without noticing or realizing the change, I left food on my plate instead of cramming it all in. All because I gave myself TOTAL permission to NEVER think or care about dieting. I guess it was a sort of lying to myself, a little trick ... like faking a good mood and then finding that you're actually in a good mood!
Whatever, it worked, and works. I think that the best way to let go of food issues is to REALLY LET GO of food issues. Shut the mind out and let the body take over.
With regard to veganism, it's so hard for me to believe that ANY "treat" could be really, really awful. As a vegan you're already eating SO much healthier than 90% of the first-world population -- without even trying. So if you want a "treat," HAVE it. If you want 20 treats, HAVE them.
I know this sounds "simplistic," but this has been my experience. My friends couldn't get over my "high metabolism," but I really believe that it's largely a state of mind. The only "diet" that has ever worked for me is the "Screw-Dieting Diet."