What Causes Tight Foreskin Which Does Not Extend?

I am a 22 year old male and have the following problem: I have an issue with my penis, The foreskin is very tight and I have difficulty pulling it fully back. Especially when erect. Once it is back, I have even more difficulty extending it back to its original position, I have attempted stretching exercises, and although they do help, I find the next day I have the exact same problem