We used to joke about my gelding being an accident (though, I'm thinking he was nothing comparatively!) . He got so tall so fast and didn't quite grow into his legs until fairly recently (maybe more like 5 or 6 years ago, he's 14 now) and was so clumsy. He always had bumps, bruises, cuts and scrapes.
He's got a big scar across his hock from trying to jump out of his stall. He was 2 ish and had just come back to our barn after staying at my uncle's house (he came back because he jumped my uncle's fence and was running around town). I went out to feed one night and saw him from the barn, lying down. Nothing unusual. But it hit me that he was OUTSIDE of where he was supposed to be. I ran down to him and he had his hind leg stuck up in the air between the horse panel gate and the post it was chained to. He was still kind of unruly at the time and I, as a 12 year old, freaked out thinking "How on earth am I going to get him out!!!?"
Luckily, he realized he wasn't getting out of this without my help and by the time my Grandpa came out to help me I had managed to undo the gate and free his leg. He had a pretty yucky cut, but otherwise was fine.
He also was often seen limping, but it magically cured itself before the vet could ever make it out... ugh. That poor vet got lots of "Never mind" calls. (Don't worry, his usual vet check cleared him as healthy)
He still hasn't really grown out of the hurting himself phase. He is really good at making an injury just scary enough for me to freak a little and call the vet, but just ok enough the vet doesn't need to see him (which I am thankful for, but still... frustrating). He recently sliced open his eyelid (EWWWWWW I do NOT do eye stuff!!) and I followed vet's instructions and already had everything I needed and he healed up beautifully.
However, your accident waiting to happen is way more than I ever have dealt with. Good luck with that beautiful mare!!! I totally understand your need to vent.
Side tracking again, we did have a sweet little filly skin nearly her entire hind leg below the hock (tendons showing and everything) and she recovered beautifully with regular bandage changes and care. I don't remember exactly what we did as I was young, I just know I never want to do it again. It halter broke her really quickly too.
Again, Good luck! Fingers crossed it will end soon.