Jumping on the saddle fit bandwagon as you will have a terrible time fighting a saddle that doesn’t fit you correctly. I am guilty of (previously) saying “oh its the way you sit if you have pain/can’t sit up, etc.” because I had ridden in a huge range of saddles - dressage, roping, endurance, jumping - without pain ever and able to adapt. So I was pretty sure all these people complaining about pain were just sitting wrong. Oops.
THEN I met my nemesis with some sort of wintec on a lesson horse. It wasn’t too small. I have no idea what the problem was, but it just about destroyed my “nether regions”, canter being the worst. I begged for mercy and my trainer let me borrow her saddle - problem solved. Round 2 with some sort of german dressage saddle. No pain, but I could not feel my seat bones no matter what I did. I couldn’t even tell what I was sitting on - it was like I had no butt… Weirdest experience ever. I actually couldn’t tell where my upper body was in space, or how I was being supported. It was almost worse than riding in the crotch killer.
Can you try other saddles, even if it means riding other horses? Might be enlightening.
Editing to add I looked at the saddle pic - to my eye it looks pretty deep with a steeper rise (although I prefer a flatter saddle so my eye might be off) - in a deeper saddle make sure it is big enough or the rise will get you.