Diagnosis help (24M)

(24M) Hi, throw away for obvious reasons. I work in the military so I can’t get an official diagnosis without getting kicked out. To get straight to the point whenever I masturbate to characters from media i like. I feel terrible afterwards and hurt myself. Ive cut chunks of skin out of my penis and even shot the top layer of skin with a gun. Afterwards I feel so bad and cry tears at “cleansing@ myself with self harm. With the exception of all that my life is great, wonderful family, I enjoy work. I have few good friends but I get along with almost everyone. I just want to knoe whats wrong with me if it’s something besides general mental illness.