hi there

As a long shot, have someone screen you for autoimmune disease. Lupus can include mental instability due to the disease affecting the brain, plus it can cause PN

BUT: it would also be causing joint pain/swelling, skin rashes etc etc at the same time, and you don't mention these. But it would be worth having someone run an ANA anyway, preferably when you are experiencing these symptoms. If it was positive (and to be significant it needs to be a good strong positive like 1:320) then further testing would be warranted.

Like I say this is a bit of a long shot as you have not reported any other symptoms and lupus is a systemic disease, but it is probably worth running an ANA anyway.

hth
raglet