Mom 2 months out post knee replacement surgery

Hello, i am super worried about my mom's recovery. I am the youngest 24F daughter out of three and my mom is 70 years old. She is having intense pain in her hip and lower back is this normal???

I think she is also dependent on her pain medication, she has been taking 10 mg of oxy for over two years and it is not working anymore. Last night she told me how she is having "bad thoughts" and SI.

I am really worried and was curious if this is common pain for people who are older. Can pain medication stop working like this as the person becomes more adjusted to the medication? how do i help my mom not be depressed?

i am struggling mentally with this, i'm in full time grad school and it is hard to hear how badly my mom wants to die and i really don't know what to do. How do you manage your depression after having this surgery??

thanks