I take 300 mg lithium, 90 mg Cymbalta, .05 clonazepam and now my psychiatrist has put me on 20 mg Prozac which I am supposed to raise to 40 mg this week. I have been on the Prozac 21 days. I am exhausted and can barely function. Nausea and headaches. She does want to wean me off the Cymbalta in a few months. Will this get better?