There is a high liklyhhod that you have some muscle damage to the thoracic region of your back. You should see your family doctor and see if he concurs and if there are spasms, maybe he will prescribe some form of muscle relaxer and a mild pain med along with rest and possibly ice/heat and physical therapy.
If you are at the begining stages of having back problems, I would advise you to begin going to college now and try to get a bachelors in something that is not going to be too physical, the reason I say this is because I am in the same shape you are in now. I was making close to 80k a year as a power plant shift supervisor and now I am disabled and cannot go back to what I know. I have to start over and it is really hard to go to college at 33 with a 1 month old baby and terrible back pain still.
Dont hesitate to go to your doc and if this is work related, claim it. I didnt and I will be without disability pay by the end of next year. Not a good life choice for me!