Why do I scar so easily now? Doc says no thyroid issue, inflammation or iron deficiency. Hair/nails brittle skin/scalp dry, teeth pains/white tongue.

Nutritional issues. Have you had a physical with bloodwork? Some of the symptoms can be due to vitamin deficiency. The bloodwork should point out where the deficiency exists.
Possible infection. Tooth pain and a "white tongue" could indicate fungal infection, poor oral hygiene, over use of antibiotics, nutritional problems, etc. See your dentist.