I know this is distressing and depressing, but try not to let the lack of diagnosis get you down. When it comes to unusual stuff, it can take years. It took so long for my partner to be diagnosed with Endometriosis, hEDS, and POTS, literally years for each one individually. She struggles a lot because many of the things that could help her interact badly with her other meds, so she has to pick and choose what to “treat.”
Anyway, the amount of time it takes can be brutal, but don’t stop looking for answers, and don’t stop advocating for yourself.
Also, try to minimize the amount of time with your mother if you can, because that certainly isn’t helping your mental state.