Going for surgery in mid-July...

I'm not supposed to do any moderate-high impact exercises for atleast the first 4-6 weeks after surgery. I'm so used to doing 5-6 days a week of moderate-high intensity cardio (trying to lose the last 10 pounds), and I'm concerned about putting on fat or losing muscle, mainly concerned about losing muscle though, since I've been lifting quite religiously 2-3 times a week for a few months now and have been seeing great results.

If I stop lifting completely for 4-6 weeks, will my muscles start to shrink to my skinny-fat pre-weight training days? Would I have to go back to lifting 5 pounds weights when I go back to lifting after the surgery?

This is probably dumb and I should be more concerned about recovering to my healthy self after the surgery, but I'm working my butt off to lose the last bits of fat on me, and I'm trying not to let it go to waste.