Struggling and being in pain must be the hardest thing to watch.

I guess if your apple cider vinegar is raw you will be getting some ferment benefit from it but to be honest, it's not something I know enough about to say whether it would help. I can't see it hurting! Fermented veggies should help though. I find sauerkraut a little fiddly and time consuming with cutting all that cabbage so carrot sticks or radish slices could be a good one for you to do. Super easy just fermented in a jar with salt for a few days- loads of instructions online.

It is so hard to move forward and introduce new ideas and troubleshoot when you're tired. I know it well and I really feel for you.