Swollen lymph nodes from mid-july, just went down last week. they waxed and waned a lot. dont have gla fever. also had brain fog recently. what is it?

Lymphadenopathy: It is important to diagnose your condition - and anything with the lymph nodes I regard as 'serious'. Since you've had symptoms for a number of months, you need to see a doctor. There's a list of different infections that could cause this, and possibly other diseases too. Lymph nodes are an important part of the immune system and therefore you need to get this checked so you can get better.