What Causes Pain While Deep Breathing?

one day i felt a pressure on the left upper chest right around my heart. The deeper i breathed the more pressure was felt. I decided to breathe as deep as i could to test the parameters and felt a POP around my rips. The next day that region was slightly sore but i was intoxicated (under the influence of alcohol) so the effects might have been dulled. Today which is a day later, every breathe i take all day, around the same region i experience pain with. Even with slightly shallow breathes I experience slight pain and can feel the constatn yet mild pressure whenever I do not breathe. Stretching in the "chest going forward sholders moving backward" motion causes alot of pain in the same area.

I am a smoker
I had a dental infection for nearly over a month while on a trip
I am 24 years old
Work from a computer and until recently have had very little exercise
But recently have been pushing my body 3 times a week with weighted training
Diet has been poor recently past two month have seen an excess of fast food
I am 6'1 165lbs
And i have been taking lyrica for rls for about 3 weeks

What could this be, a rib or muscle injury or could it be a heart condition. My concern is it could be something poking my heart.

Please get back to me.
-David