I Have Been Taking Tegretol For 2 And Half Days

I have been taking Tegretol for 2 and half days and don't want to take it anymore. I have already gained 3 pounds and am concerned about all the side effects. Including side effects of going off the meds. I am taking 100 mg 2 x a day. I took 100 mg once on Friday, twice on Saturday and once on Sunday. Will I get side effects going off of medicine now.