Thanks for sharing your knee and leg concerns with the FATD community. I am sorry to read about this. I would be happy to offer you my thoughts, tips and suggestions. Did you have any trauma to the leg? Have you ever? If not, then it is not likely that you have torn your ACL. In addition, sometimes hip problems lead to referred pain in the knee. I am not sure where the ‘ripping’ feeling is. At times, swelling in the knee makes it tight and the feeling of pulling or ripping can be felt upon moving it. Thankfully it has only been ongoing for 2 weeks or so. I am an advocate of using anti-inflammatory medication (NSAIDS) as long as your doctor permits these types of medications. If so, please take it with food. Lowering an inflammatory reaction (from overuse, degeneration, soft tissue tearing, etc.) can help ease the bothersome feelings you are having. I also believe in regaining or maintaining a full range of motion in your hips, knees and ankles (and lower back). If you gently and on a daily basis put your ‘imperfect’ leg joints (hip, knee, ankle, toes) through a range of motion, it will help keep the joints healthy as well as the muscles. Over the next two weeks, and two weeks after that, I am optimistic that you will feel better. If not, then I would suggest consulting with a medical provider for a good physical examination.
Here are some great range of motion exercises:
https://www.pop-doc.com/browse.cgi?category1=Maintain&CGISESSID=e1b529efc880b4a79b47fd390aad331d
I hope this helps.