Can 2 huge swellings above each butt cheek eventually shrink, migrate downward, and create a small mass that presses on nerves and create the pain i feel when i sit down? been 5 years since ski fall. drugs and scs no longer give relief?

The superficial swelling of butt cheek is probably not responsible for the pain you feel. The swelling if superficial like you give impression is unlikely to press on nerves. It is likely to be fat swelling and it is difficult to predict what may happen to it with time. The pain may be due to muscle tension or nerve compression by deeper structures.