My toilet tank doesn't fill. I removed the shut off valve and no water is coming through the pipe. I use pex. It has been there for 3 years almost. In the bathroom, the sink and tub works fine. Its just n water for the toilet tank.

If you are on a slab, the pipe may have been crushed by settling. If you are on a crawl or basement, look for a crimped pipe. They are supposed to use turning bend guides but I see PEX installed without them.