22yr old female feel dizzy when i move my head and slight nauseous. can walk normally. takin sertraline 100mg?

Possible BPPV: You may be describing a condition known as BPPV (benign paroxysmal positional vertigo)...common in some young people who are active in sports such as running, jumping, intense movements, etc. Check with your doctor and they can examine you for it to see if that diagosis fits. If so, try not taking more medication before trying to treat it conservatively using specific exercises.