Hi, thanks for writing to HCM.
From the given description, I feel that you have suffered a SOFT TISSUE INJURY
either inside the knee joint or outside the joint.
An MRI scan is mandatory to diagnose the exact problem.
We cannot simply keep guessing about the possibility of injury either to meniscus
or LCL based on the symptoms alone.
In the meantime, use ice packs, rest to the injured area, elastic compression bandage if there is any swelling, analgesics like motrin
Consult an orthopedic surgeon for further workup and management.
Hope this information is helpful. Good day