Are you sure you are setting the saddle far enough back off the withers?
A very common problem is that we all tend to snug these saddles right up
on the wither--causing pinching no matter how nicely it appears to fit.
I hate to say this, but you might want to consider a different
saddle...maybe a Sport Saddle?
Your instincts are good--get a knowledgeable person to evaluate the
saddle on your horse, with you mounted also, and don't have it be a
saddle maker 'cause, guess what, they'll be trying to sell you THEIR saddle!
Diane @ Safe Haven