36 year old with EDS and sagging rear - what treatment would help with this? (Photo)

I’m 36, f, 5’7”, 135 lbs, I have Ehlers Danlos Syndrome & in my teens I lost 90lbs. My butt has started sagging, and I’m wondering what are the best treatments for dealing with this. I’m concerned about the loss of volume & thinning skin. I’m also spanking fetishist & I want to make sure that any procedure I do won’t get in the way of receiving impact after recovery.