Unfortunately, you are going to have pain for a while. This surgery causes a lot of trauma to your knee, and even your whole leg. The surgical instruments used are basically sterile carpentry tools! You had 2 bones sawed and drilled and then metal implants pounded into those bones.
Complete recovery takes an average of a year, but that doesn’t mean you will have your current pain for that long. But this recovery is a very slow process.
I, too, was shocked at the pain level I had after I got home from the hospital. I was so unprepared for this recovery. I had a partial, and everything I’d read about it made it seem like a minor surgery. I learned afterward, from Bonesmart, just what all had been done. I was quite angry and offended, that my medical team had not been more up front with me
Don’t worry about doing a bunch of exercises, they are not essential. What is essential is just basic movements to keep the joint mobile. Those walks to the bathroom will do that.
Reread the Recovery Guidelines and follow them.
Make sure you are icing and elevating. Take your pain medication as prescribed. Set an alarm so you don’t miss a dose. These early days are really tough, but things will get better over time.