I would guess that much of the weight that you are losing is water weight. It is easy to associate weight with muscle mass but just because you lost weight while being sick does not mean you are losing your muscle. Make sure to keep drinking plenty of fluids so that you do not dehydrate.
Even...
20 years ago:
405 x 8
495 x 2
210 @ 5'7"
Within the last two years or so:
320 x 8
360 x 4
225 @ 5'7"
Good luck with your squats but just be mindful of your shoulders when doing them. Having the bar across your shoulders and holding it in place during squats puts a lot of pressure on them.