I have mid back pain leveled to my rib cage, my abdominal muscles feel like theyre contracting and is difficult to take a deep breath?

Nonspecific: Unfortunately this is a fairly nonspecific complaint which could represent thoracic spine pathology, or a pinched nerve, or abdominal pathology, or kidney pathology, or lung pathology, etc. See a physician if symptoms are severe or persistent.

??: Hard to say / could be a problem with the spine at the thoracolumbar junction ( where the ribs smeet the low back) or even possibly pneumonia it should be checked out by a doctor promptly.