Hospital Said I had Chest Strain.

I am 28 yr old female, use to smoke (been cig free for 33 days) recently went to the hospital via ambulance had problems breathing, felt as if someone was sitting on my chest..(chest pains began 2 days prior to major pain) as well as this pain I was experiencing numbness/coldness in my left arm (also numbness and coldness in arm began the night prior to major pain) After x-rays, scans of the heart and brain the Hospital said I have a Chest Strain. 3 days after being released from the Hospital and I still feel a noticeable discomfort in my chest (all upper chest) and I have noticed I am short of breath after I walk for a bit, or when I am having a conversation with someone. I was never short of breath even after I quit smoking now, total days of OVER all issue have been 7 days now. I am just curious as to what this might be if not Chest Strain...also there is nothing I can recall physically that could have lead to Chest Strain or a Strain of any other kind.