Cyberia C

For a long time now I have constant shoulder and chest pain, on my left side. I've had ECGs, some x-rays, a couple of years ago I had an MRI, I go to physiotherapy, but nothing helps.

The pain is piercing around the lower edge of my ribs and under my arm, form time to time, as if someone was pinching me, but there is also a dull ache across the shoulder and I'm totally stiff in the muscles behind my left shoulder blade. Physiotherapy doesn't help, despite the exercises. I'm so worn out every day, I just don't know how to cope anymore. I get tired and work is so difficult because I have to sit down which further increases the stiffness in my back. Any ideas?

I'm in my 40s and am overweight, although I'm generally healthy.