Saggy skin, HELP!!

I am 8 months post-op and i have lost 170lbs and have 100 to go and the skin is crazy. What do you guys wear as far as foundations for under clothes. I have one that I love but I need more and it is the capri legnth bc the mid thigh ones roll up on me. HELP PLEASE!!!

I wear Spanx sometimes, but my sagging skin problem isn't really that bad. Unfortunately plastic surgery is really the only fix for it.