What Causes Recurring Tongue Sores?

Question : Hello, for about a year I have been getting reoccuring tongue sores. This happens almost daily. They will generally start to heal by morning and start to form again during the day. As far as appearance they are smooth spots with a white outline/boarder. They only occur on the front and sides of the tongue. I know geographic tongue is the first thought but these are very very painful. Actually the only part that hurts is the white outline which is usually in a circular pattern. my tongue also in the front can look bare with large tastebuds like a strawberry but this is not always. I've been to the doctor and even had a colonoscopy to rule out Crohn's. I also had an Ana test which came back negative. One doctor mentioned Behçet's but was not certain. The sores look like geographic tongue and not typical ulcers. I will say at times it's possible that they are worse when I eat but b/c it happens daily I'm not sure that it is an allergy. And if so it would have to be with something I eat daily I guess. It's pretty overwhelming and right now I don't have insurance so I just wanted a general idea of possible things I can look into when I do go back soon. I know you are not able to diagnose over the Internet but any ideas would be appreciated. Oh I would also like to mention I was given a steroid. Prednisone where I took 2 a day for 5 days and in this time I had no sores. Great for me but soon after the sores were back. So I'm wondering is this yeast, std such as herpes, autoimmune? Again any small amount of suggestions would be appreciated

however she said the iron was not too bad. Could even a little low cause such severe pain and sores daily for over a year? Also if a nutritional deficiency why would the steroid help? Sorry for so many questions haha just want to make sure I cover everything. As far as stress I think I am fine besides the daily stress of having the spots on my tongue. Would they still be considered ulcers even though they don't look like typical ulcers and more like white outlined circles? Again thanks so much for helping. No doctor so far has mentioned a possible deficiency. So far it has been Behçet's, Crohn's and one suggested that I bite my tongue unknowingly but I am certain that is not what is happening. The Behçet's came from there being blood and visible mucus in my stool. Not sure how much that affects my tongue but I thought maybe I should add it. But with the colonoscopy everything was normal.