Really need help/ not sure if i have dermatitis

Hello everyone, a couple months ago i was diagnosed with seb derm from a dermatologist after havng facial redness for 2-3 years. Its on my eyebrows, in between them, all over ny cheecks nose and chin area, i also had some on my chest and neck.. My question is, is it possible that i dont have Seborrheic Dermatitis on my face? She prescribed me nizoral shampoo and creams and they actually treat the seb derm on my body but had 0 effects on my face.. It actually made it worse and gave me some scarring after a couple of days. After trying one more cream cream from another doctor and some pills that broke me out in rashes on my body i turned to diet. Removed all the Sugar and junk and ate healthy for about two weeks. Yet 0 f***ing results and no improvement!! WTF is wrong with my skin

I was thinking about a 1 day Water Fast to see if that would help. Only one day because im 5'11 - 6'0 ft and weigh 123 pounds lol. Is it possible that im deficient in some vitamins. I think my problems started when i went on a bulking diet 2 years ago to gain weight, i think i might of gained it too fast and caused some immune system damage because i gained 30 pounds in a month.

Anyway thanks for reading any help would be greatly appreciated guys !!