I agree, I think I'd get the mattress down and put it on the floor for awhile and see if that helps. If he's sensory seeking he might be sensory avoiding in some ways as well, and perhaps the loft wasn't the experience he was expecting. It might have taken him some time to figure that out.
I have a kiddo who used to push his feet into me all night too. It went on for years but he doesn't do it anymore.
Some extra propreoceptive input during the day might help.