I cracked my neck and i think i may have done something wrong because my back/spine started hurting right by my right shoulder blade. what did i do?

Nerve or muscle: You may have pinched a nerve or stretched a muscle. If you have any weakness get it evaluated soon. If no weakness or numbness, use some stretching and moist heat. If no better in 7 - 10 days, get it evaluated.

Hard to say: It is hard to say and there are a number of possibilities, from a simple muscular strain to a disc herniation irritating a nerve in your spine. If it does not resolve, consider being checked. Usually a detailed exam and appropriate studies will determine the use and whether any treatment is needed. Thank you for the question.