Suggest Treatment For Swelling And Pain In Knee After Hitting

HI, I am 27 years old, female, 5'8" and 160lbs. About 4 days ago I slipped on the wet deck and I hit my knee on the deck board. It just bruised a little and hurt to touch. Yesterday, I was milking our goats and when I tried to get the one out another one tried to get out, and so I tried to push them back with my knee and I hit it very hard on the metal gate right on the kneecap. It was very painful and I couldn't walk very well after that. It's swollen and is painful to bend it at a 90 degree angle. It's made the rest of my leg ache really bad. It's very painful to sit in a chair and not put it up. Any help would be great. Thanks!