How to get rid of Body Odor?

Okay so i've been exercising lately, and after awhile i shower to get rid of the odor, and after i sit and go on the laptop and play. After 45 minutes or so, my body odor starts to come back, and this kept on happening for the past week. Ever since summer break it started to act up..... I stopped using deodorant ever since summer break started, i used it today but the odor from my armpit was still there, smelling so ... T_T'' . I use a deodorant called Secret but i'm guessing that isn't needed to solve the problem right!? help? ]: