01 Tundra antenna replacement?

I have a 2001 Tundra V8 2wd 4 door. As I was driving down I-10 in the LA area a cardboard box flew up and crushed my antenna. Here is my problem, it bent the fender around the mount, I fixed the fender but still can't get the mount tight. That little "bolt" that goes below the mast and holds the mount up out of the fender is as tight as I can get it. IT STILL MOVES!
Do I need a new antenna mount? Was this thing glued in place from the factory? What gives? If I need a new mount any Idea how much I will pay for this. Really tired of my antenna pointing towards the back of the truck as soon as I start driving.
Thanks for the help.