Knee injury question???????????????????/?

Honestly, with the knee instability that you experienced it sounds like you might have torn something like your medical collateral ligament. Most likely you'd need an MRI to really confirm it, but a doctor would also be able to get a pretty decent idea by doing a couple of diagnostic maneuvers. It may not have torn all the way, but it sounds like you are re-injuring it pretty regularly which will lead to scar tissue and longer term damage. I'd go and get it checked out. Volleyball is tough on the knees (as you know!) and you may require a brace to play. Hope your knee heals quickly and doesn't take up too much of your season!