I'm 29f, healthy weight, neck/upper back pain for 2 yrs, back spasms last thurs so severe I had to go to er. Also recently developed yellow sclera! Help!?

Yellow sclera. I'm more concerned about the yellow sclera in your eyes than the back pain for 2 years. It could mean something is going on with your liver - something you should see the doctor right away for. It probably doesn't have anything to do with the back pain that's been going on for 2 years.
Jaundice. Maked think of liver or pancrease problem get it lookrdat by primary care watch tylenol (acetaminophen) intake.
See a doctor. Yellow sclera is a sign of liver disease or even pancreatic cancer (the disease that killed steve jobs) and should be evaluated by a doctor. Neck and back pain can be coming from disc disease or arthritis. You should see an orthopedic surgeon and get x-rays. Depending on what the doctor finds, an MRI may be obtained. Acute onset of yellow sclera should be evaluated right away, don't wait on that.