I also have a ruptured disk in my neck and working too long can make me sore for a long time. I use a lot of the same techniques that everyone else uses here on the board. My physical therapist also said that when you sew you should not only keep your spine in line with your head, but you should also move the top of your body forward along with your sewing rather than just extending your arms. She said this puts less stress on your shoulders. I have to keep remembering this - old habits are so hard to break.
Another product to use for aches and pains is called: Arnicare Gel. It is a homeopathic product and you can find it at Whole Foods, CVS Pharmacy or at health food stores. It doesn't smell and isn't greasy. When you put it on you'll suddenly realize hours later that you don't hurt anymore.
It is good for use on bruises, it makes them go away a lot faster. By accident I also found out that it was great on burns. I was holding an old style travel iron, the kind that the handle folds down and the handle slipped out of position and it folded over and burned my arm pretty badly. I put the Arnicare Gel on it right away and the pain from the burn was immediately gone. The burn also seemed to heal faster. Now I keep a tube of it in my sewing bag and offer it to my sewing friends at the Senior Center when they start to complain about soreness.
I hope you feel better soon. Take care.