I have had bariatric surgery (10 years ago). I've had hashimoto disease for 35-40 years and inject 1cc vitamin B12 per month. I have had low B12 and vitamin D levels. I've lost 15 pounds over the last year due to lack of appetite, wake up tired, and have stomach pains that I think were due to drinking coffe, iced tea, and white wine on an empty stomach. Should I see a hematologist or gastroenterologist ?