This seems like a place to moan and groan, so I will, because I want to.
Oct. 2020, some spazzy blue belt ripped an "ankle pick" from my knee cut pass, which I realize in retrospect was like doing a heel hook with a rowboat motion. My knee popped, then I fell down, my knee popped and then he fell and top of me, and there were like 2 more pops. I was in horrible pain and couldn't walk.
Turned out I tore my LCL off the bone, my ACL was totally torn (reconstruction), my MCL was 80% torn (repairable), my PCL was torn (40%, sprain), my thigh and calf muscles were torn from the stress, and one of my menisci was blown out. The doctor asked me if I was in a motorcycle accident when he first saw my MRI.
Surgery, Nov. 2020. Walking again, Feb. 2021. Cleared to train LIGHT, July 2021. Future path is full clearance to roll "hard" Nov. 2021 (though if I'll be brave enough, who knows). Expected full, 100%, feel great recovery, Nov. 2022.
Shit sucks, but there's a way through it. I've had to ask myself some really hard questions ("why do I do this, do I want to keep doing this, will I keep doing this, is it a waste for a 2nd degree black belt to quit, etc."). I don't think there's any shame in quitting a sport that's hurting you, but you also have to weigh out yourself as a person. Unfortunately Jiu Jitsu is the only sport I've ever been mediocre at, so I keep coming back to it like an abused wife.