@yellowspain - if you look at the article I linked above, you'll see it talks about refeeding syndrome potentially involving phosphorous, potassium, thiamine and magnesium. It does not involve all the vitamins and minerals and amino acids. That would be very difficult to sort out.
There's a reason Freddd wrote so much about potassium, and there's a reason there's a whole thread by richvank (which I also linked above) talking about why potassium is so important when starting methylation. It's not a coincidence. That thread also includes a study showing that people with ME/CFS have trouble maintaining potassium levels.
Many many people on Phoenix Rising have needed extra potassium when taking B12 or methylfolate. It's not just any old vitamin or mineral - it's very specific. You can safely test this by drinking several glasses of vegetable juice which is high in potassium.
This is exactly what happens with refeeding syndrome - an initial improvement followed by negative effects as one's potassium drops. It takes a few days for that to happen.
These very well can be symptoms of potassium deficiency. Just google potassium headaches and you'll see it. Potassium deficiency can make you very tired (happened to me) and of course depressed then too. It's hard not to be depressed when you feel so crappy.
No one can guarantee results for you. But I've never heard of anyone being harmed by drinking tomato juice unless they're allergic. I suggest you forget about paradoxical folate deficiency for now and concentrate on the most likely cause of negative symptoms, after first feeling better and then worse when starting to take folate.