well...im pretty sure what cause my back problem...I work at a daycare and I got 2 four year old boys to help me move a playhouse made out of a cardboard...not heavy at all...but 1 of the boys lifted it really high and I hurt my back.  this happy 2 weeks ago...so I was in pain for 2 weeks but now it hurts a lot to cough, breath, sit and now its a burning senstation...
It looks to me that you have developed acute back strain. Because muscles are in spasm they appear tight. I know that this condition is causes severe pain. First take bed rest, do not bend your back or walk unnecessary. Also take painkiller and muscle relaxant like moral or MySpace. Heat application through cloth or water will also help. Burning sensation suggest there may be a slip disc also, for which tablet gabapentin will help. If burning sensation increases you need to get MRI of your spine.