I was told i had serotonin syndrome from all of the anti depressants i was on. they took me off every one except one. now i feel like i have the flu and im really tired and nauseous. is this normal?

Not normal: In a situation like yours there often is difficulty deciding whether you're experiencing a type of withdrawal symptoms or a relapse of depression. An experienced psychiatrist is best qualified to determine this and treat and follow you. If increased therapy is needed such as increasing an ssri or combining it with a tricyclic antidepressant, it requires skill experience to avoid side effects.

Common: It sounds like you might be having some withdrawl symptoms from suddenly stopping medication that increases serotonin. It should decrease and go away in the next few days . If not better in a few days let your prescriber know. Best Wishes