1. from childhood, had sores in mouth, blisters in groin region, underams, and pimples.doctors used to give b-complex, over years effectiveness went down. recent thyroid tests didn't show any problem.

See dermatologist: I suspect you have some type of chronic hereditary skin condition, something like histiocytoiss x, just to name one. I would urge you to see a dermatologist, perhaps even a pediatric one despite your age, and discuss skin biopsy with them to see if condition can be identified once and for all. Only then can appropriate treatment be initiated.

Biopsy: I suspect you have hailey-hailey benign familial pemphigus or one of the variants on epidermolysis bullosa (photo guy). If the lesion has been biopsied, see if you can get the report. Neither is curable but both are somewhat manageable -- you'll want to get a competent dermatologist. Your acne, if you have it, is a separate issue.