You have some digestive issues that make absorption problematic and perhaps the gut is permeable. Omega-3s (non-rancid) help the gut heal and become less permeable, reduce inflammatory response, and many others. You more than likely need 3+ grams daily of Omega-3s. Wean up from 1 gram, watching for any reactions.
Sublingual methylcolbalmin (B12) may help as long as you allow it to stay under the tongue for 30+ minutes. It's a bypass way of absorbing the methylated B12 versus the low absorption in the gut. Usually, gut problems will impair absorption of B12, that's why I mention subligual.
Consider at least 200mg of magnesium daily in an acidified form like citrate or malate for better absorption.
Trimethyglycine (TMG) + B vitamins help me out with low energy and stressful conditions. I take a product that contains 500 mg TMG, 12.5 mg B6 (pyrodoxine hydrochloride), 400 mcg Folic Acid, 500 mcg B12, and some grapeskin extract with red wine extract (polyphenols) per pill. The TMG requires a B-complex to aid in homocysteine control, otherwise you may not receive the TMG benefits.
Have you tried Kefir for probiotics? There are brands, if you can't make it yourself, that do not use any milk or milk-products, if you're sensitive to lactose/dairy. I've seen the Lifeway brand at many stores, it tastes pretty good in my opinion. Shorthand: Cultured foods that you can tolerate.
I noticed you wrote Iodine, but have you tried SSKI (super saturated potassium iodide) in conjuction daily? For example, Iodine in the AM, then SSKI at noon?
EDIT: SSKI also means Saturation Solution of Potassium Iodide.
Gut repair is of utmost importance, I cannot reiterate that enough. Omega-3s are a start from detoxified Fish oils to balance the 3/6 ratio and control inflammation in the body. Isolate amino acids did not do anything for me in the past personally, but I did not delve too deep into them.
Sometimes, I personally take a high quality multivitamin. Some ways to tell if there are good ingredients is by looking at the "type" of vitamins/minerals the manufacturer uses. For example, methylcobalmin is superior to cyanocobalmin; thus, methylcobalmin in the list would score the multivitamin +1 points over other brands with inferior vitamins. Another example is Magnesium oxide, it's a cheap mineral added to supplements; thus, you'd want to avoid it.