So Tom and I just got back from the stable. Gem has some lower lumbar pain (most likely from what he's done in the past along with an ill fitting saddle, The saddles we have used on him, have fit him fine, so we know it's not us. It was most likely when he was a trail/lesson horse)
And he has some sensitivity in his right front hoof. And he has arthiritis in his hocks, and right knee. The vet said that was a big cause for him to buck. So i'm actually glad he did buck me off, or else we never would have found this info out.
So we're starting him on bute for about 3 weeks to see if there's any improvement. He's going to get hand walked 3x a week too. Tom has officially retired Gem from any more saddle work. It's very upsetting. He's only 8 too.
The vet said that he really is young to be having all this arthritise and thinks the problem is whatever he did before we purchased him.
So that's what's going on with Mr. Gem. But at least we know why he was acting the way he was. It's such a shame though