I've been on 20mg of Fluoxetine for nearly 3 weeks now and just feel awful. Feel tired all the time, really drugged up but can't sleep well at night. Drop off really fast but at about 5am I keep waking up and can't go back to sleep. Just feel shattered all the time and also quite sick. Is this normal and when should I start to feel better? I'm on the meds for anxiety. Thanks