Rash that started and cleared on my chest but for over a year and a half has not gotten better. spread for over 2 years to scalp dandruff and sores, peeling behind ear, itchy smelly groin and upper buttocks? lost insurance in between jobs due covid?

Rashes are very difficult to diagnosis without looking at them. From your description of where it has traversed, I would be very suspicious of a fungal infection. These can be notoriously hard to treat, as it can take months of medication to clear them, especially when they involve the scalp and nails. Most oral anti-fungal medications are very good, but need careful monitoring by doctor.