If you just stopped taking them, then aggression might just be only one of the side effects. You should never stop taking a medication like Sertraline without talking to a doctor as they must be reduced really gradually. Please start taking them again, or at least go straight to your doctor and tell him you have come off them and see what he says. Maybe at least take one ever two days for two weeks, then every three days for two weeks and so on until you are taking one a week for two weeks, then half a one a week for two weeks, then that's it, you should be free of them. This is how I had to reduce. I stopped taking another similar anti depressant before just like you and ended up trying to kill myself, it was all down to the tablets. Then when I tried to stop taking Sertraline, my legs stopped working, so I carried on taking them and went to see my doctor, who put me on the reduction programme I described above, it really does have to be done that gradually. The aggression is bound to be part of it, I hope you sort it out soon, and well done you for wanting to be off the tablets, but please, do it the way its meant to be done, and save yourself the aggro. Good luck, and God bless.