Hi Minh
Just short and sharp cos I am supposed to be elsewhere but lorazepam and temazepam are mostly the same thing - they are both benzodiazapines (benzos. Strikes me that you need something to keep you asleep rather than the short acting benzos.
I am not a doctor but a nurse from a very long time ago so don't take my word for it and ask your doctor about all this (it is too complicated for me).

Managing pain medication is really complex which is why they have doctors and nurses dedicated to pain managment. Ask if there is a "Pain Managment Team" at your hospital and see if they can have a look at what you are on and what you should be on.

good luck, will try to get back to you later.

Karen