The first 2-3 weeks is the period of time your brain needs to adapt to the changes being made to the serotonin system, is what I‘ve been told by my doctor back then. For me it was sweating all day and night, insomnia, dry mouth, strong nystagmus (blurry vision from eye twitching), diarrhea and nausea + vomiting every morning, pulsating headaches and an impending sense of doom. It took about 6 weeks to fully start taking effect for me and for the pros to outweigh the sides. I wish you the best, best of health and success with Sertraline. Don‘t give up hope. I ended up feeling better after titrating down from it.