Pain and Swelling at Knee. 3 queries.

Pain & Swelling at Knee:- I was hit by another man and fell down. This was happened 2 months ago. At the time of incident, I was unable to stand on my own and sat in the chair for 1/2 hour and slowly went in to my house. After applying massage at pain areas (like middle of lower leg and bone which connects to knee joint), I was able to walk but with pain. I took pain killers and gentle massage at pain areas, felt that pain was reduced, but the pain & swelling at knee joint area came again after pain killer tablets usage stopped. Now, I am able to bend the knee at certain extent and getting pain when I try to stand up from ground sitting. Recently, I took acupuncture treatment for 1 day to reduce the pain & swelling, but no change after 3 days. I would like to know what could be the reason for not reducing the pain & swelling at knee, what kind of treatment I need to undergo, which doctor I need to consult. Appreciate your help if you provide responses to above 3 queries.