Try pinking-shears!

Is that 21 yrs or 21 months old?

If it is causing a problem with your erections, then go see a doctor. Otherwise, keep it clean and you will not have problems. Those of us that are cut wonder why our parents put us through this trauma at such an early age. Your dick size is genetically programed-not much you can do about it.

you can buy a clamp which you wear for about three days and then the skin falls off but you may still need to go to the doctors to get the anesthetic. and not sure about penis enlargement I know there's always places promoting pills and such but doubt they really work, I think masturbation helps keep it long, or hard pulling.

Cant think why the size causes so much angst. Strech and pull it for all your worth and it will simply go back to its former size. AS for your foreskin if its not causing medical problems it may only be a fashion thing.
I am sure there are some who have attempted self circumcision but also sure they later regretted it. A surgeon knows what he doing, you wont.