Repair circumcision. The only thing you should do is to see your doctor to be examined so you can receive proper treatment. Do not attempt any self treatment. Consider psychological care if this is causing you mental pain.
Undo or repair? Circumcisions can be revised by a urologist if done badly. However, first seek psychologiacl help if you mean that you are upset by having had a circumcision. Uncircumcision surgery is a major undertaking and performed by very few urologists or plastic surgeons. Operation consists of seperating a lot of penile shaft skin and pulling it over glans then covering the denuded part of penis with graft.