I had a very narrow foreskin as a kid, I got all kinds of painful infections. The doctors wanted to circumcise it, but I was terrified!

As I got older, things eased off and relaxed, especially when I was masturbating a lot.

The first time I pulled it back was painful, but it got easier every time, now it is completely natural.

I'd suggest trying to work it back a tiny amount more each day in a hot bath. Eventually it will relax and move back. Don't forve it, though!