Shortness of breath, feels slightly constant, no other symptoms. sometimes also feel a pain in right of back when trying to inhale all the way. have a history of anxiety, but would that be causing this?

Panic attack?: I would say get yourself a thorough physical to rule out any physical cause(s) for these symptoms and any others. If nothing is found, then get yourself an evaluation by a psychiatrist for anxiety/panic disorder, and seek psychotherapy.

Pleurisy.: A proper diagnosis requires a medical exam plus chest X-rays. Pain with taking a deep breath is called "pleuritic" pain, usually reflecting inflammation of the lining of the lung; this is termed "pleurisy". It could be due to a virus, pneumonia, a blood clot in the lung's artery or other rarer causes. The lung exam, X-rays and a breathing test should clarify the cause of shortness of breath.