I did steep turns in a pa28 also and had the same initial fears. I kept thinking I was going to fall out of the sky at that angle. Once I got over that though it was easy enough to get it right.
I just roll into the turn and get my bank right with the real horizon then verify with the AH. Once you have the bank right just pick a mark on the windscreen (usually a squashed fly!) and keep it in line with the horizon. I nailed it every time using this method
Good luck!