Knee I thought had healed, gave way last night - help needed

Hi,

A year and a half ago, I damaged my ACL in my right knee. Since then, I have felt it getting gradually stronger.

Last night however, whilst at a martial arts class, my knee gave way and I fell. I felt the same burning sensation I did when I originally damaged the ACL, as well as feeling as if my knee was twisted. Thankfully the swelling is not too bad, and the little swelling there was has gone down. However, it is sore. Sore to bend back and sore when pointing my foot upwards. I can stand on it fine without it giving way, and even hop on it - which is great (I assume).

My question is, how should I got about healing it? I have access to a gym. Should I rest it for a couple of days, or go to the gym and hop on a stationary-bike or do some (very) light leg weights? I have a resistance band from when originally damaging the ligament, should I use that now?

I am desperate to get back to my sports classes, and I'm not going to rush back and potentially worsen the injury.

Any help would be greatly appreciated.

Also, I purchased some cream that claims to help joint pain - I'm a bit sceptical, do you know if they work?