This started after I adjusted the water shut off valve that leads to the toilet. I was attempting to increase the amount of water in the base of the toilet. Now I can't get it to stop humming. I've tried to readjust or put it back to where it was, but unsuccessful. I know the humm is coming from inside the wall. What did I do? It's only occurring in the one bathroom.

You have a defective washer in the fill valve/ball cock or a loose washer in the stop valve (the thing you are adjusting). Look inside the tank and tell us which of fill valve you have.

You cannot adjust the amount of water in the bowl (base.)

Type B