I only ralized that the skin was soppsoe to slide over the head of your penis last year and I am now 18. My forskin is very tight and hurts a little when hauling it over. When it gets over my head and down a little it is very red and has a even darker red at the bottom or the head, almost purple, I play hockey so everyone showers together and I noticed that other heads are mostly white. Also on my penis there is a little smell always from it. If there is anyhting I can take or do please let me know thanks

Sounds like you may have phimosis.

Caring for the uncircumcised penis

This site will tell you about the phimosis and the care and hygiene you need to do. If it is really affecting you and is painful and stays red/purple/painful, you will need to see a doctor, they can probably give you some type of treatment or discuss circumcision with you.