Excessive Masturbation. Life in future.

I started masturbating at the age of 12. Since then I masturbate on a regular basis, 1 - 2 times a week. Now I am suffering from  masturbation addiction . Night fall occurs if I don't masturbate for 7 to 8 days. Also I ejaculate very early . Sometimes sharp pain occurs at the tip of the penis . The size of the penis is smaller than average which makes me worried and  sometimes it shrinks in the middle when not in erect state .Sometimes I masturbate in the middle of night while in deep sleep which i come to know about in the morning. I feel it also affected my mind as i am not able to concentrate much on anything. I feel weak and depressed most of time. I never had sex till now  but I am worried for my sex life in future.