This can be repaired.
Lots of information about repair on the web. Rather than fibre glass, my material of choice would be carbon fibre on the inside and an aggressive 2 part adhesive (speed grip) to fill the seam. I used fasteners with backing plates to fasten it together then I applied adhesive in the seams and around any hardware that was going to remain in place. Followed up with carbon fibre. Filled, sand, primer then paint

I’ve used it with success in my wing repair (exact same process) and for the fabrication of the rocker panels.

if you have the desire, you’ll be able to do this. The only person that will ever know it’s been repaired will be you.

Time and patience.

PM me if you have questions, I would encourage to dig into this, review all the material you can locate on the web and get up to speed before you attempt it. Knowledge = confidence.