I have been having pain in my upper spine area where my neck is and when i tilt my head back it feels like there is liquid and then it pops and hurts?

Rheumatism: If you were older, i'd suspect degenerative arthritis in your cervical spine, but at your age, it's more likely to be a muscle sprain. This is a good indication for seeing a chiropracter who may be able to provide symptomatic relief. Alternatively, you can wait it out till it gets better on its own. Heat, rest, and analgesics often help.