Re: it feels like something is wrong but why can't anyone figure it out?
You seem specific enough about your symptoms that you should be able to look them up prior to your doctor's visit and come up with some possibilities for diagnoses. I usually tell people not to try to figure out their diagnosis before they go to the doctor, but in your case, you've already been and s/he hasn't been particularly helpful.
Try using sets of symptoms in a google search and see if you come up with possibilities -- such as dizziness, tingling and poor memory... then look further into anything it turns up and see if you have even more symptoms. By the way, I just did that search and it turned up fibromyalgia -- so maybe you want to check out more about fibromyalgia.
See if you can come up with 2-3 possibilities, then take those to your doctor and ask him/her to help you DISprove those, instead of proving something else.
Good luck! Let us know how you make out....