Your resin isn't bad because you ran out of salt.
You need to do 2 manual regenerations back to back with no water use during or between them, at the max salt dose for the volume of resin you have; that's 15 lbs per cuft.
Depending on your salt efficiency, you need to use more potassium than sodium chloride; +12% if set at 6 lbs/cuft, up to 30% if using like 3-4 lbs/cuft.
I strongly suggest the use of solar crystal salt. It rarely bridges and totally dissolves, pellet type of any kind doesn't