Is It Normal For Masturbation To Result In Burning Sensation?

im 18 years old, after i masterbate, the tip of my penis hurts. and gives me a burning sensation. Lately the colour of my urine has gone from yellow, to a dark shade of reddish yellow. i also have a serious itchin problem inbetween my thighs n the groin region. please doctor with all due respect tell me as to what i have? and for further information, when i pass faeces and when i wash, i see drops of blood on a white eggish type of fluid that comes out after the faeces. just so u know, i once earned a small slit in my rectum, and i got it treated, im jst wonderin if they are all linked to each other! doctor please help me out i just turned 18 and am freaking out by reading about these fatal diseases that can be in that area!! so please tell me as to what i have, what i should do to cure it, and what i can do to prevent it without lettin it become worse!!!