Does this sound like a lateral calateral ligament sprain or a meniscus tear?

i cant streighten it and it hurts when i try and when i bend it. It is also swollen and has stayed the same for 6 days. I got it by twisting my knee when it was bent. and it hurts to walk. which does it sound like? also it hurts under and like on the bottom of my knee not really the sides.