It's a good fit in the front, but the back panels are too angled for your horse's back. They're putting extra pressure on the outside
Of the panel. I would scoot it back about 2" as well.
If you don't want to get a new saddle, try a ThinLine Half Pad
or Skito Interpad
over your quilted pad. It will help eliminate those
Pressure points for you, and is cheaper than a new saddle
If you want a new saddle, then look for one with flatter panels on the bottom, not so curved or angled.