I have a potted hydrangea. The leaves are pale green and look droopy but are not soft to the touch. Have been watered regularly.
Hydrangea need plenty of morning sunshine and then afternoon shade when in containers.
Check the soil daily. It should be moist but never soggy. Let the top inch of soil dry between waterings. In warm weather you may need to water twice a day. Make sure excess water can drain from the container.
Hydrangea can suffer from wilt if they are in the hot sunshine.
You an fertilize your potted Hydrangea with a water soluble fertilizer with a 20-20-20 formulation.