Still in pain three months after THR

I recovered well after my hip replacement and was discharged by surgeon after six weeks. I am now back to long walks with my dogs and can climb over stiles etc. I no longer walk with a limp. However I am still in pain and it feels like the arthritic pain is still there (although I know that's not possible). It sometimes feels like sciatic pain and goes right down my leg. It is worse in bed. Physio said it was possibly because other muscles are having to work now as I had been walking so different for years because of the pain and stiffness in my hip. To be honest she wasnt that helpful and didn't really give me any answers. I have found more advanced exercises on YouTube that I am going to try, but was wondering if anyone else has experienced this. Any help would be really appreciated as I am so disappointed and upset about this. Thank you.