Sorry to hear that you've got OA in one hip. Have you had physio yet? I have OA in my right hip, also in neck, lower back, ankles and fingers.
I was sent first of all for physio and given a set of exercises. You can find these exercises online, and they have helped a great deal with the pain. I don't want a new hip if I can possibly help it as I know it's not necessarily the answer to everything and know of many people who are still suffering pain afterwards.
OA is always painful first thing in the morning, and I do a series of exercises for back, hip, neck, etc etc before I get out of bed to help with mobility.