I have had five different surgeries in the past year, all different body parts. I had my second full knee replacement at the end of December. There are different types of knee replacement. Both of mine were the ROSA method. I have a very high pain tolerance, but if yours is the ROSA method, you are going to need pain meds. I took percocet for 5 to 7 days after the surgery, and managed with 500 mg methocarbamol at night only, so I could sleep. Methocarbomol is a mild muscle relaxer, and it provides the surrounding muscles a break.
Make sure you have a cooling machine (like a small ice chest with a pump, hoses to circulate cold water, and a cooling pad, it will be indispensable. Many hospitals are not properly equiped to cool the knee after surgery. Typically, they use one of those bags with a screw top that they put ice in. But someone will cross thread it and it will leak. The knee needs to stay dry, so bacteria is not introduced. And, the cooling machine is so much more efficient. If your insurance won't provide one, I can give you one, but you need to come get it.
I have a bunch of tips for you, PM me your number and good days and times to call, and I will discuss them with you.