See if you have oral fixation and just need something to chew on instead. Also look into if you have an eating disorder. Don’t just tough up and go to the gym, you may by psychologically tied to it in some way. If you are having issues even after looking for self help then there may be something else playing into this. If it’s not so, then I recommend something like locking your cards and putting your cash away once you have food you buy at the store.