knee pain

the other day I jumped off the couch and landed wrong and hit the floor quick. it was so painful! I couldn’t stretch out my knee and it locked up on me I couldn’t bear weight on it and that lasted for about 3-4 days. I thought the swelling and pain would go away but it seems as if I cannot straighten my leg out fully and when I walk on it more than 30 minutes straight it becomes so painful that I don’t want to walk anymore and it begins to swell up again. i’ve had a previous tear of my acl and had acl reconstruction done in 2012 I don’t think it’s my acl so what do you all think it could be?