open sores around anus, need diagnoses

I have had this re-occurring rash for about 1.5 years now. It seems to come and go every week. Maybe sometimes more if i put my body under stress from drinking. I have been blood tested for herpes twice now, and both times have came up negative, iv gotten several STD checks, and everything comes up negative.

It comes so fast and heals so fast, it sometimes itches and is very painful because its open sores so its constantly bothersome.

I feel like its some sort of infection or something because it appeared two days after i slept with a new girl.

Ive been to 4 different doctors including dermatologist specialists and have been given cream to try to kill it but it just keeps coming back. It has to be something that these doctors dont know about.

its a skin problem is that mabe yeast or some kind of eczema the creams can tske up to 10 days to work sometimes longer on depending on what it is