Did the soil fall off the rose when you were moving it out of the old pot into the new pot? It sounds like their may have been some root damage. If this is the case, I would move the rose into a shady spot in the garden, and keep it watered well, try to get those roots growing again. Do not fertilize it. Did you fertilize it and perhaps use to much fertilizer after you transplanted it? Just some ideas, really hard to say without having seen you transplant it, and how you transplanted it into the bigger pot.