I feel your pain. I am - or use to be - a runner and was sidelined by injury for four months. I am now trying to get into it and am finding all of these new aches and pains. My knee is one of those pains. I use a patella band that velcros right under my knee to help keep it stabilized. That helps me significantly, so worth while to at least mention to you. Obviously, make sure you listen to your body - you would generally know if there was a tear or a serious injury. Sore muscles, however, are a good thing. Like James mentioned, protein is great to help your body recover. Doing some different curls with hand weights is great too, like Alice mentioned. You can ever sit on an exercise ball and do them! That will help your balance and keep the blood flowing. Good luck - you got this!