I don't think you're a quitter, either, but in this case, it's a no-brainer. Quit.
Playing 2c-5c online would be like torture, especially if you're playing against a bunch of kooky boys who never saw a 7-2 offsuit they didn't love.
As for your knees, I know it sucks. About 15 years ago, I tore a lateral miniscus playing beach volleyball. Had it scoped and the doc told me I'd be looking at 6 to 8 weeks of recovery time. In truth, it took about a year before I could walk without pain. Now I'm fine, but my tear likely wasn't as bad as yours. Was yours an ACL tear?
Joe Namath had his knees operated on like 6 or 7 times, but kept delaying having them replaced. When he finally did replace them, he said it was the best thing he ever did. YMMV.
I don't like or trust most surgeons. They have a service to sell and they often minimize the recovery time while overstating the benefits of the surgery. They're basically salesmen with a scalpel.
Anyway, quit playing online and play more live. Becoming an online recluse would be terrible.