What does a stomach Ulcer feel like?

A couple months ago I took too many pills and I was vomiting and had a burning stomach for a week. I couldnt eat anything. Ever since then I have to watch what I eat. If the food has to much acid in it my stomach will burn all day. i can’t even eat tomato sauce anymore :( I was just wondering has anyone experinced anything similar to this? Is it an Ulcer? Is there any use in going to the doctor?