I don't know why, but unfortunately you can't run, you can only move slowly. Does anyone know what it could be? I wish everyone a nice day. And thank you if someone can help me.

There are certain places in the game where you are locked to crawling (this has been known to glitch, and remain even though you should be able to run), but my first guess would be you are carrying too much weight, and are slowed down as a result.

Check your inventory, and sell or drop what you don't need, and see if that does anything.