Over 80% of all cases of Seborrheic Dermatitis , chronic acne, rosacea, psoriasis, pompholyx, ulcerative colitis, crohn's diseases, and hundreds of other health problems are actually induced by Antibiotics and other prescription medications that have potential to cause irreversible damage to intestinal microbiota, skin microbiota, liver and kidneys.
Welcome to the club!
If you take an FMT from a very healthy person, you may be able to quickly reverse the damage Antibiotics have dome to your intestinal flora.
With every day you are living with imperfect microbiota, it will be more difficult to re-establish the healthy microbiota, once you actually do everything right.
If not an FMT , try to get some raw milk, make home made raw milk yogurt and hope it is enough to reverse the damage to your intestines and the damage to your microbiota.
Learn also about liver flushing, your liver most likely needs some help, as Seb derm is a liver disease that shows on skin.