Hi there,
Shortness of breatahing could be due to many many causes. There is a long list of these, like:
Chest infection
Asthma
Allergic reaction
Panic attack and anxiety
Heart failure(waking during night because of SOB, frothy pink phlegm, using more number of pillows than before)
etc. etc.
You must not ignore this. Get a proper diagnosis and treatment before situation gets too complicated.
Best of luck !