Vicky, I know how you feel. I hate clay that's too soft, and a few years ago all the clay manufacturers changed their formulas to remove pthalates, which resulted in all the brands of clay getting softer.
I know a couple of strategies that might help you. One thing you can do is to leach the clay. Cut it into slices or work the clay until it's smooth and then roll it out flat with a roller or a pasta machine. Then stack the clay in layers with white paper in between. Any kind of non-waxy or glossy paper will do. The paper will absorb some of the liquid plasticizer, leaving the clay stiffer. If it's still too soft after leaving it overnight, try again with fresh paper.
If you feel that your warm hands are the problem, another strategy is to put the clay in the refrigerator or freezer before you work with it, and then if it gets too soft in your hands, put it back in the freezer for a while. Chilling the clay won't hurt it, and cooler clay is always stiffer.
Remember that you can bake polymer clay multiple times, as long as the temperature doesn't get too hot, so sometimes it might be best to work one area of your project, then bake it, then fill in another area, so you can't mess up details you've already finished.
I hope one of these strategies works for you! Good luck.