Dead Outlet--GFCI RESET button stuck
A GFCI is a safety alarm, which detects problems in other devices.  Its one job is to trip when another appliance has a problem.  It is testing all the appliances all the time.  If an appliance has a problem, it will not reset. That is its job. 

I imagine with this GFCI tripped, a bunch of sockets are dead.  Unplug everything in those sockets.  

Now go back and see if it will reset.  

If it does, then the GFCI did exactly what it's supposed to.  Now start plugging things back in.  One of them will trip it.  That appliance is dead. Unplug it and take it to the repair shop.   Did that fix it?  Done.  

OK next. Everything's unplugged?   OK. 

After you do what ThreePhaseEel suggests, remove the two wires from the LOAD terminals.  

Now power the circuit back up and see if the GFCI will behave normally.  If it does, the problem is in the downline wiring.  Or an appliance you haven't found yet!  

If it still won't reset, then yeah, it's the GFCI.