First, you need digestive enzymes. You are probably deficient in the nutrients that your body needs to produce stomach acid. The enzymes will help your body digest your food until you can repair it and reverse the deficiencies. Your body needs adequate b vitamins to produce necessary stomach acid, niacin specifically.
Eating fermented foods like raw saurkraut (that hasn't been pasturized) with your meals, taking bitters before meals to stimulate digestive juices (HV suggests just a few drops of a digestive bitters tincture on the tongue is all you need), and digestive enzymes that include betaine hcl with meals. Probiotics are important too.
Raw apple cider vinegar in water is good for the digestion too.
Getting on a good comprehensive vitamin supplement (you may need several like a b-complex -- 100mg, multi-vitamin, sublingual b12 -- 1,000mcg methylcobalamin, vitamin A (palmate, not beta carrotene), vitamin D) and a good chelated multi-mineral to help reverse deficiencies. You may find you'll need extra magnesium.