Hi Sydney!
I would be weary of just removing the topper as it might be the mattress causing problems too. If you were having back pain on your mattress before the topper, and it stopped with the topper, then you probably still need at least a topper. Maybe the topper was too firm, though, and it will need a replacement with a softer ILD. Or maybe you do need a new mattress. I would keep your options open as removing the topper will probably only bring back your old back issues.
There are tons of places on this website to read about back pain/hip pain and the possible causes. One I know of is here: https://forum.mattressunderground.com/t/futons-looking-at-otis
Maybe Phoenix can help get you in the right direction 