Seborrheic Dermatitis and Stomach Ulcers: What Is Going On?

Hello everyone, as I'm arriving to my wits end. I'm writing this down hoping someone would guide me through what might be going on with my body, I'll be genuinly thankful for every possible help.

The sick journey started back 10 years ago, with stomach pain, I kind of ignored it since it wasn't that bothersome. As it worsened through the years, I suddenly started suffering from Seborrheic Dermatitis on my scalp which led to gradual hairloss. As soon as I realized the possible corrolation between the gut and autoimmune/skin conditions, I started dieting (Acid, Sugar and dairy free diet) while supplementing (12 months of Mastic Gum and oregano to kill H Pylori, casual supplementing with B, D vitamins, L-Glutamin for stomach lining) which kind of helped soothing my gastric ulcer for some time, but the conditions are still there. I've visited many doctors but they keep focusing on the symptoms giving me topical treatments but I know all of the symptoms are caused internally, but still I couldn't figure out what is behind.. Any suggestion would help,

Here is a list of my symptoms:

- Seborrheic Dermatitis on scalp (Most bothersome)
- Gastric ulcer (Most bothersome)
- Cracking knee joints
- White fissured tongue
- Dry skin
- Cold hands and feet
- Vertical Nail ridges
- Shortness of breath
- Gastritis
- Low cognitive ability
- Anxiety Tweet