I get the same thing. And yes for me its stress. Sharp pains come out of no where. I have found a muscle in my back below my shoulder blade. If I rub it OMG it hurts. And is a huge knot. I try to work it out when I can handle it. Which isn't often.
Check the way you are sitting. Make sure you not hunched over.
If you think it is food related. Which it can be. Are you eating fresh garlic? Types of chili? Soda, acid related stuff? Fresh onion? To much pepper or salt. A lot of fried foods?
Sometimes even eating healthy can cause problems. Which include the fresh onion. Some people can't handle it unless its cooked. Garlic is a common problem for a lot of people. Including me. I can have ground dried garlic all I want. Fresh is for the birds..lol
Chili powder, bell peppers, green chili can cause problem. Chili powder is a common ingredient in many foods. I use it a ton.
Fruit and juice. Both very acidic foods. Yes healthy but again acidic foods. Try making smoothies. Or having small amounts of fruit with cereal. Something to counter balance the fruit. Acid relux can cause pain in both sides. But usually you have a feeling in your throat. A need to burp or cough maybe clearing your throat. Like something is kinda stuck and just wont go down. Also a taste in your mouth usually acidic in nature. But can be all around not a pleasant taste.
But like I said before can also be muscle tension. Try relaxing baths with bath salts or epsom salts. But limit your time in with these as they can cause urinary tract infections if you sit in the bath for hours. Try some way to relax. Reading, writing, breathing techniques. Start a journal keep track of what goes on from day to day. You would be surprised what you will forget the next day. Something small that might of upset you more then you thought. Journals are a great way to write your days events and move on instead of caring on your shoulders.
If the problem persists be persistent with the doc. You might need an antacid or a muscle relaxer. You might need to see a chiropractor. Or a much needed vacation.
Never give in if your not satisfied.
My problem is both acidrelux and tension from my anxiety/panic attacks. And the fact I hurt my back several years ago and it has just gotten worse over time instead of better.