Hi Marky,
Sorry about your situation. How old are you?
When all the normal things are 'gone', and you’re bedridden or house bound, you are forced to face life in a new way, and at least temporary (because I am sure you will be fine eventually) find joy in new things. And this is tough mentally, no doubt. And often extremely depressing.
My best suggestions for coping with a situation like yours is a) Try to keep things in perspective – difficult I know, but still. Although it kind of destroys your normal life, this situation is only for a limited period and fortunately a limited problem compared to for example serious disease. But at the same time, don’t feel bad because you feel bad for having a ‘non-serious’ problem! These knee problems can really mess up your life. However, remember, you will get better. b) Still try to accept that life comes with obstacles that many of us face at one point or another. This was so difficult for me, as basically everything had gone my way up until my knee broke down. c) Try to immerse yourself with indoor hobbies such as reading, studying, personal development, watching TV series, playing video games, origami, catching up with old friends online or over phone, or whatever. Google 'indoor hobbies' for ideas! During periods of being more or less house bound because of knee problems, I have for example, read a lot, explored new music, new podcasts, new people and cultures (through books and documentaries), new TV series, immersed myself in astronomy, started playing chess, explored myself, my beliefs, and my entire take on the world.
Good luck with your recovery and keep us updated on your progress!