Hypothyroidism, Pinched Nerve In L5 And L4, Scar And Rash On Left Leg.

I have hypothroidism, & ADHD; I also have a pinched nerve in my back (the L5), a partly pinched nerve in my back (the L4), and they believe the L5 is entrapped in the ankle area of my left foot by scar tissue . I had the rash for a year, and then it suddenly just began to blister , which as i said when the blister burst, that left an open wound , which when healed left a scar. The scar & rash had gotten better since being on the thyroid medication, but today the whole area of skin peeled off, leaving a huge red, raw, bleeding (only in small spots) open wound, which stings and burns like crazy. This is on my left leg, on the shin . What is causing this? A doctor told me that the scar was a scab and that all scabs eventually come off, which is true, but when they do, they leave new, healed skin when they come off. Not raw, red, bleeding skin. But the doctor I talked seemed to think this happening was fantastic, and implied that it would keep happening, each time getting smaller and small. But this time the open wound is larger than before. Please help.