When I was in college I used to call it "backpack back"--it's frequently accompanied by a strange, sleepwalk-like gait! When you carry an unnatural weight for a prolonged period, your body and muscles will compensate by shifting alignment and building muscle. If you're experiencing pain and discomfort, you need to find a different way to carry your books asap, because if your spine is affected you could be doing damage that may show up to plague you later in life--if it waits that long. Try a book satchel with a single shoulder strap to wear cross-shoulder--and every couple of weeks switch shoulders. It may be uncomfortable or inconvenient, but when you're 55 and spending your last dollar on physical therapy, considerations like that pale to insignificance. Also, you might want to pop into a gym and tell the personal trainer what's going on. He can show you exercises that will compensate for the backpack's pull on your back and neck by strengthening the right muscles.
Regards.

get up against the wall, put your head on the wall but look straight ahead, feet up against the wall also. The hardest part is keeping your head agains the wall. This is a neck stretch.

A shoulder stretch: stand straight but not against wall, put your hands in front of your chest, facing up to celing and try to touch hands together, and your arms are bent at elbows and tucked into your sides. Then slowly move the hands to the elbows out toward your sides, keeping the elbows tucked in.

Good luck.

Michelle

Strengthen your abdominals. And practice rolling your shoulders down and toward the center of the spine to open your chest.

as many, as slow as you can
and i make a moisturizing rose cream, the scent is calming.