Well, now you know a little secret about recovering from joint replacement surgery. It is a BIG deal. When the surgeons talk about 6-8 weeks "recovery" they mean the incision is healed, the implant is knitting into the bone, the muscles, ligaments and nerves have begun to heal.
What they don't talk about is how unhappy all those body parts are at being manhandled, that muscles and tendons get weak and stiff, there is a lot of bruising inside and out, and that nerves take a very long time to heal. So ice, ice, ice, move the knee as much as you can, elevate I when you are sitting or lying down, and control the pain with tylenol or ibuprofen.
After shoulder surgery in October, I iced for 4 months, alternated ibuprofen and tylenol for a couple months (I'm still using one or the other a couple times every day) and I'm just getting ready to start the final phase of my PT.

Be kind to yourself! And keep moving.

You are early in your recovery phase. Sleeping in a recliner may be bending your knee too much. It can get stuck in that bend. You need to try to flatten your knee as much as possible (0* extension in Physical Therapy). This position was very hard for me from the get go.
And I was told to sleep on my back to keep the knee straight as it was healing. Ice machine, eye cover perhaps, pain medication as ordered. It's the hardest surgery to recover from and truly it takes up to a year to recover!