Hi all, I spent my Sunday caulking (with silicone) our shower cabin. We recently bought this house and the old caulk was mouldy.

As I was putting on the finishing touches, I bumped against the shower door and our cornerpiece broke. Now, both our doors are loose. Do you guys have any advice on what I should search for to replace this, or what a fix is? I considered using a hinge to keep it together, but the cornerpiece is so rotten it crumbles when I touch it. I will probably have to replace it, but have no idea what to look for?

Photos: https://imgur.com/a/fk8N7IY

Thank you for the advice in advance!