Bathroom gfi won't work
it won't let me reset it


If it used to work, and you have not changed the wiring:

It's either defective, or there is a ground fault. They do seem to fail on a regular basis in the long view (I average 10-15 years, from what I recall of my GFCI failures.) But a fault of exactly the sort they are designed to prevent is always a possibility, until it's eliminated as a possibility.

If it never worked or is newly installed:

There's the additional possibility that it's wired incorrectly - incoming power goes to the "Line" terminals, any power going beyond connects to the "Load" terminals. When wired "backwards" they don't work.