Suggest Cure For Muscles Spasms In The Back

I was massaging my lower left side of my back, above the hip and a little to the right, when it started to spasm. I was just applying pressure with my fingers -- massaging the area. I have been working out and lifting weights heavily for this soccer season. This happened three days ago. Now, the pain will reside when I sit still or keep it in a steady position when walking -- but when I 'tweak' it, the pain returns and I am either completely stiff or in too much pain to move.

I am a college soccer player, and need advice on how to fix the pain. I have a huge soccer tournament this weekend -- and am wondering if I should play. I did play an indoor soccer game the day after I injured my back, I took 4 advil and applied IcyHot every twenty minutes. The IcyHot numbed the pain and I could play -- but was limited on my acceleration. When the game was over, I had spasms for two hours once the IcyHot had worn off. It's been three days since the pain started.

What can I do to increase my recovery rate? What do you think is wrong -- I pulled a back muscle? Should I play this weekend -- will the muscle get worse?