Dear one, you have a history of localized pain in back, mild in character on rest,with running and buring, but more on moving your arms, with a duration of 7 to 8 weeks
As per your thinking its becasue of hit by a stone, but to me it seems it more than that, its essential to get it evaluated, by a doctor, so that the cause can be ascertained, what worries me more is the duration of your pain.
Next Steps
Consult in person to a doctor for an examination and help.