Ditto the suggestion on working with a knowledgeable saddle fitter. If you don’t have one in your area, please let me know where you are, and I’ll see if I can give you a name. If there’s no one in your area, fitting can be done long-distance through the use of back templates and photos by a shop or fitter who has the experience and ability to work that way. ( and both have experienced long-distance fitters who could help you.
"It's saddle fitting - not rocket science."