I sometimes masturbate after like a month and a half have gone by. i want to stop because i know it is a sin.?

i play for my church band and i love God with all my heart. i just feel the urge so strong and thoughts overtake my mind. when i am finished i feel relived and the thoughts are out. but i feel extremely guilty which is a sign it is not something God would approve of. i know im not the worst person out there but this has been a problem for the majority of my life. Advice?