Hi, Ive Been Sick For Two Months Now, It Started

hi, ive been sick for two months now, it started with the sensation of pressure in the center of my head and heaviness in the head, it is not a headache because i tried relieving the feeling with aspirin but it never worked, then it followed by severe fatigue and nausea, feeling of loss of ballance specially while walking (like waking on pillows), dizziness made worse when entering a shop or a place thats full of stuff i always feel that my eyes are rolling everywhere and that i cant focus and feel that i cant control my steps, the symtoms were getting worse by the time and after a months of the appearance they were unbearable, i went to an internist told me i had stomach and colon inflamation, i took the medications including bepra, gastreg, unasin, the symptoms got better after a week but then i completely crashed in the second week and i had consistant nausea and vomiting, stomach ache, severe headache, complete loss of appetite, i stopped the medications for 2 days, then the morning after i woke up with a swollen knee with severe pain, went to a doctor and found out i had knee inflamation and some weird stuff and he gave me another list of medications including augmentin and after two weeks now the knee is much better, but, i have been getting episodes of nausea and today i had that feeling of fatigue and head heaviness and nausea just like before, i am currently on no medications and i dont know whats wrong and am having a very hard time living a normal life while having a ton of work for college as well, please help.