I have numbness and tingling in my hands and feet, primarily on left side, I also loose strength in the left hand. I have sever joint pain and at times swelling in my lower legs and ankles. For six months plus I have experienced sever fatigue. Within the last month I have had a break out of herpes 1, stress ulcers in side my mouth on my gum line, and most recently (48 hrs ago) I broke out with shingles on my left side mid back towards my arm pit. I have had blood work done, they have ruled out lupus and mono. The only thing on my blood test is deficient in B12, it was 172. I have received 2 B12 injections within the last 6 weeks, my level is now at 396. Note, I had the gastric bypass weight loss surgery in 2012. What type of doctor should I see what test should be ran to find out what is compromising my immune system?