I’m lucky in that I’m very content to pour a can of beans on rice and call it a meal. But I can sympathize with your situation. I’m very sorry to hear about your mental health. If I may offer a suggestion, if you can’t be 100% vegan, then just be as vegan as you can be. Choose the shirt made from cotton and not wool. Experiment with vegan food a little bit at a time and learn what you like. Buy the fake meat when it goes on sale. Maybe it’ll work out, maybe it won’t. But if you take it slow and gently then you probably don’t have anything to lose.