Talk to Orthopedic Surgeon on Pain In Upper Back

I have pain in my upper back, mainly between my shoulder blades. It usually happens when I have to stand in one place for some time while doing household work, such as making rotis, cooking, or ironing clothes. As the pain increases, I start feeling like I can't get a satisfying breath or that it's difficult to breathe properly.

The strange thing is that the symptoms improve almost immediately when I lie down. Once I'm lying down, the pain and breathing sensation settle.

I also walk for 3 hours or more every day without any pain or breathing difficulty. The problem mainly occurs when I'm standing in one place for a prolonged period.

I do have health anxiety and a history of panic attacks. I've seen doctors many times in the past (though not recently), and they usually told me it was due to anxiety and weakness. However, I now eat a well-balanced diet with three proper meals a day, along with fruits and milk, but the upper back pain still continues.

The last time my oxygen level was checked (in January), it was 99%.

Could you please advise what this could be and whether I should get any tests or an examination?