If you are waking up stiff and getting better as the day goes on, it could be arthritis. But it could be other things as well. I think you have suffered with these hip problems long enough and should go see a doctor

I think a new bed will help, at least a little. Your bed is so old!!! A new one will be a great investment. Do you know what you are looking for as far as firmness? No matter what, I think you will feel like you are sleeping like a queen when the new mattress arrives