I Have Handjob Daily. I Want To Quiet. I Couldn't

I have handjob daily. I want to quiet. I couldn't stop the handjop.iam a sport's player in athletics I have selected for state athletics meet. I have this problem so I feel my sports talent is going down. So please please please please please help me.I want stop this habit.this is urgent plz plz plz plz plz. .......!!!!!! Plz help me. .......!!!!