How can i stop being horny while studying?

Hey am 16 ..used to be a bright student ..now from my 5 grade..i got addicted to masturbation ..not heavy ones ..usually till 3 times ..some times .Anyways i thot it of a sin ..and i stopped it in my 6 grade ..and my marks wer considerably bettr ..2 nd rank to be more precise .However presently my urge is too much in my 9 th and 10 th grade .I some how managed my 9 th ..But 10 grade ..i kept flunking in my exams .I couldn concentrate in my cl cuz i alaways feel horny..even i misunderstood for ADD/ADHD or learning disabilities ...I am 101 % sure that i dont have any ..but am alaways anxious and frustrated.I alaways have this urge to tease my genitials ..yet i cant just keeep my hands off it .My bords are just one month away ..and i need to prove myself again ..I seriously neeed some help ? if there is natural way i can reduce my drive or some how balance my urges ...PLEASE?:\