I also used to shoot canted, and now shoot upright with bow straight up and down, Rick Welch style, Ray touched on the most important thing, it will seem strange at first, but give it several months and it will feel 100% natural. I also shoot with a Cavalier elite tab with the thumb piece, I'm not promoting using this tab although it is also a big part of my becoming a much better shot, but only mentioning this because at first the Cavalier tab felt completly unnatural but after several months it was completly natural, and now I could not imagine shooting without it, or shooting canted, give it time, shooting uprigh and you will be glad you did.