How can I get rid of muslce pain?

so i started relay about a week or two ago, and i think i sprained my muscle in my right thigh. anyways, when i run, it feels like somebody is stabbing me in my leg! i strech my thigh a LOT more than other muscles, and it doesnt work. I was wondering if y'all know any way to numb the pain or something? the meet is in like 2 weeks, and i have to run, cuz our team has no alernate. HELP ME?? is there like a muscle pain reliever or something that works?