Pain in chest area

[Doodlesmgee]

Hi, i am a twenty year old guy from Idaho. I smoke lightly, mabye at the most seven cigs a day, and have for a while now, been having some strange things happening. i have noticed that after i finish a ciggarette, i feel really short of breath. Not like panting or anything, but when i breath in, i feel like i am not getting the air i need. I also get short on breath when talking to people, i run out, have to stop what i am saying, take a deep breath, and start over. Usually this only happens when i am excited, the talking part that is, like when i am upset, or mad. I also sometimes get a feeling, when i am sitting down, that my heart just starts pounding. Really hard pounding, like i stood up, ran in place really hard, and sat back down. It persists for about ten minutes, twenty minutes, then subsides. I also get a problem when i wake up in the morning from time to time. I will wake up on my back, and the area around my ribs on the sides and front is just in agony. It cant take a deep breath because it is absolutoly painful, and it feels like there is a weight on my chest pushign down and putting pressure on my ribs. If i streatch or anything, the pain worsens and gets more intense. I have to grit my teeth, roll over, and get up and stand up and move around for about two or three minutes before this feeling goes away. i sometimes get shortness of breath with it as well.  I am overweight and pretty out of shape, in my line of work, it doesnt leave much time to exercise sadly, even though my workplace has its own exercise facility in the building, none of us use it, because we have to be on the phone all the day, and have to be infront of a computer while on the phone. And most of us are so tired and stressed after work, that we just go home and crash out. I take zanex because isuffer from panic attacks, and depression and anxiety, and zanex helps mellow me out and stave off panic attacks when they happen. I am worried that i might be having small heart attacks or something, and am really scared about the pain in my ribs in the morning, and the beating of my heart when it starts pounding for no real reason. Thanks guys...
Chad