Can you tell us what doses you use for your supplements?

Do you use enteric coated SAMe? Enteric coated SAMe bypasses the
stomach... it doesn't dissolve until the intestines. (it is not stable in stomach
acid).

Except for the SAMe and B12, most other vitamins should be taken with food.
SAMe is best taken first thing in the morning at least one hour before food.

Sulfur is very plentiful in the diet, you would be eating far more sulfur containing amino acids daily than are in SAMe.. which BTW is a natural substance your body makes. (your body does not make, vitamins--they have to be taken separately.)

Mild gastric distress is sometimes reported by people beginning to take high dose SAMe, however, I have used it since 1999, and have never had an upset. Mild distress can be avoided with smaller doses in the beginning, and I think it has to do with the fillers in the tablets, not the SAMe itself.

Your neurological issues if B12 dependent can include neuropathies including the GI tract (gastroparesis). So you need to focus on getting that B12 level up. (When B12 is very low, it becomes low in the spinal cord as well).