Since probably 6-7 years ago, I started getting this popping noise on bone between my chest when I straightened up, I didn't really give it much thought, but it did hurt when I was doing heavy bench presses.

Since maybe 4-5 years ago, I started having problems in the same area, but the back. At first, I got this numbing/tingling sensation in my front teeth whenever I sat in against a hard chair. That's gone now.

Now, it's progressed to the point where when I take a large breath, I can hear popping noises in my head most of the time, espically when I've been sitting in on my computer chair. Also, I'm unable to sit in a chair for longer than a hour or 2 without having to take a break. In the theater, I usually shift around because it's uncomfortable, It does help when I have some comfortable armrests or pillow under my arm.

It just feels like one side is more forward than the other. When I went to the chiropractor/PT/acupuncturist, they said one side is stiffer than the other, after 6 month of chiropractor+ acupuncturist, it didn't really alleviate it. I've also gone to the PT, she gave me exercises, it doesn't seem like it worked either 

They all say it's due to bad posture (I work on the computer all day), so I've used exercise balls and also standing up while I work

After about 30 minutes, I usually feel this cold/numbing sensation in the area, more so when I'm sitting on the exercise ball. Also my that area in the back felt super sore after doing heavy lifting

I've had xray/mri done in the area, but they didn't find anything.

Any thoughts what this could be???