I have been taking 250mg Lustral daily for the past 4 years. Now that my doctors have become aware that I was diagnosed with Arrhythmia 20+ years ago (lustral is contraindicated for people who have arrhythmia, and mine is fairly bad), I have to stop taking it. Just over a week ago, the dose was reduced from 250mg to 200mg, and I feel really dreadful. I have permanent nausea, lethargy, crying spells irritability and major sleep problems among other things & feel like I am really struggling at the moment. Is this normal or should I check back with my doctor?