I have a torn knee cartilage (from running fast intervals on a treadmill) and had anput 6 months of very careful "kneehab" which focused on keeping my glutes strong, and working to support & gently extend the full range of motion in my injured knees. It was a year before I did squats & I've just started running (slooooowly) again, 2 years later.
I did more bench pressing than I'd done before - my PT rarely programmes it, but it kept me lifting heavy-ish. It was about 6 months before I did deadlifts, and those were generally between 40k (my warm up weight) & 60k, so v light.
Obviously my injury was very different to yours. The focus was on strengthening everything around my knees, and getting the joint working properly again through a full range of movement: lots and lots of (unweighted) step ups onto a box, with very slow downward motion to really train all the glutes as the power house of my legs. It was hard work! Also lots of work on a Bosu ball and then the much smaller wobble balance ball.
Lots of slow slow work, mostly unweighted. I think my knees, quads and glutes are stronger now. And a year after that injury I hit a deadlift 1RM. Squats are still not so heavy, but I'm back to a training weight which is challenging.
I was seeing a physio (privately) about once a month for the first 6 months - at my age (65) injuries do take longer & I fear a weakness in my knees. I wear a tubular support bandage - I think now it's a placebo, but it does feel better than bare knees. I also warm up a lot, and get really mobile.
So ask your physio what you can do that will help keep your strength and support recovery from injury. And remember, fitness is not linear - if you've got a good foundation, you'll get back there & stronger, from all the thoughtful careful rehab you have to do. Sometimes slowing down has its rewards!