Don't Know whats wrong

Hi I am a 21 year old male, who has been experiencing wierd symptoms for a while now. I have been to the doctor and he has done the basic neurology tests and done blood work, which all came back fine. I have been experiencing brain fog, where I feel like I am on some kind of drug. I have muscle twitches mostly in my legs but sometimes other parts of my body as well, only when I am sitting. My memory seems to be not as good as it used to be. I have also recently started to have a stutter when I talk, which is becoming frustrating at times. Some times I will feel as thought there is an electric shock going through my nose. I am wondering what is wrong, the doctor also did all sorts of heart tests and they came back good as well. I also asked him about MS and ALS and he said that I didn't have it. I feel as though I am going crazy. Thanks