My chiropractor told me to stand in a doorway and put my hands at shoulder height and lean through the door, putting pressure on your upper back. I find it really helps.. Also it is so important to be working at a table/desk that is the right height.
This does work!!!! I do it every morning during my wake up exercises and I step away standing erect....you have a postural problem. Physical Therapy could teach you how to manage it.