Any enlargement techniques will possibly do damage to your penis because you are stretching and stressing a very sensitive area!
There are topical medications to increase bloodflow. If you feel you have done damage though, I would go see a urologist.
And don't try make your penis larger. If you spend time learning about woman's anatomy and how it works, any girl will appreciate that much more than a large penis who thinks he can just pump away and she'll be thrilled on account of his large penis. It doesn't work that way.
Learn some technique, no one will ever notice once you've slept with them.