If you broke the assembly as you described, you can go to any C/B shop and buy that assembly cheap. I have done this type of replacement several times.
Just unscrew the cable running up inside your mirror from the bottom of the fitting where it mounts on the bracket. Take the fitting off the bracket and take it with you to make certain you get the right parts.
If you broke the bracket itself, there are ways to attach another different type of bracket too, ask at the CB shop.