It is dying from root rot due to overly wet soil. The leaves roll like that and then fall off the stems. Peppers need to dry out between waterings and do not tolerate overly wet or poorly draining soil. Plus what size container is that it is in? It looks far too small and that would only cause the plant to get rootbound and require more frequent watering.

Yeah, root rot most likely. They like to almost dry out between watering.

Just looking at the picture from the distance of your lens, it does look like the soil is pretty wet and muddy even. Of course, it could be that you have just watered it, thinking that the curly, dry-looking leaves is because it needed more water.

The soil is pretty much sand, I changed it to potting soil and it looks much better now. They still look curly curly, but better.