I need to head out to work in a bit so don't have much time, but I've suffered with it for a few years now.
Sometimes really badly where I can barely function. I have been much better recently but going through a bit of a bad spell right now.
I would like to message you later this evening if ok? I know how you are feeling and the support I got from people who understood meant a lot to me, I would be very happy to talk to you and give you some advice that helped me etc.
BTW ulcers sometimes take days to actually hurt. I get them all the time.
For now, try your hardest not to look in the mirror. If you can't handle not looking try to gradually increase the amount of time between looking. If you are looking every ten minutes for example, next time wait for 12 minutes, then 14 and so on.
If you can manage it I strongly advise you to get out of the house and do something. Every time you look in the mirror you are feeding the beast. You might not be strong enough right now to stop looking completely but gradually increasing the time between checks is a good start.
The best thing to do right now would be going out or doing anything to try to take your mind off it for a bit. I know how hard that can be, I really do but the single best thing for my anxiety is to keep busy.