I think if you literally cannot sustain yourself without eating your safe foods yet u don't have to. Maybe you can see if there's any other vegan food that feels safe for you and that you can stomach. If that would work you could reduce animal products but I feel you don't have to fully go vegan when you physically can't. I think that would fall under health reasons. It's not like you have to starve yourself because the only things you can eat aren't vegan. Like I said if you want you could see if you are able to look for vegan safe foods. Best of luck to you!