I hate to tell you... but that is shot.
I would not want to ride in that boat
If you can't handle a transom fix like mine, there is a shorter way.
Take off the aluminum trim and cut off the 1.5" strip of glass. Use a chain saw to dig out the crap as far as you can down and sideways. Clean the inside glass as best you can and pour to fill.
It will be way better than what you have now.