I am at a loss for the correct boot size.

I rent a pair of 9s (27 cms) and they were way too tight in the toes. After just one day they killed my toes so I went one size up to some 9.5s (27.5s)

They seemed to fit fine at first and boarded for 2 days with the new boots. Had decent control but I realize now that I am lifting my heels too much when toe sliding and and causing mild discomfort in my shins and calves. I’ve tried tightening them all the way and the heel lift doesn’t go away. It just makes my calves hurt.

So if 9.5s are too big, and 9s are too small, what can I even do?