Chest pain/pressure, weakness, left side of body muscle problems. Help!

For the last couple months on and off I’ve been having severe chest pain. A sharp pain and pressure specifically in the left breast bone and upper rib just underneath. While experiencing this pain I feel nauseous, weak, dizzy, and very breathless as if something is knocking the wind out of me.  For the last three days this pain has been increasing, and more consistent. I'd really just like to go to the emergency room because now I’m finding it hard to just ignore. I’m beginning to experience muscle spasms and twitches on the left side of my body specifically in my thighs, shoulder, and upper back. Fallowing these involuntary muscle movements are numbness and cramps on top of even more weakness. I live an extremely healthy lifestyle, but lately this has been prohibiting me from doing  too much of anything physical or athletic. However, months ago when all this chest pain and weakness had just started I did notice that the left side of my body was slowly loosing muscle mass and strength. I only have defined abs on my right side of my body now, while the left side just looks like the “average” American. Where did the left side of my abs go? Same concept with my arm muscles. I’ve been told by numerous people that the body is not symmetrical, but mine used to be pretty symmetrical, and while noticing the decrease of muscle mass I began to isolate muscle groups and target work them out individually. This only seemed to speed up the process of deteriorating the left side of my body.  So pretty much I’m experiencing heart attack-like symptoms, and the left side of my body is weakening drastically. What should I do? I’m uninsured and can hardly survive paycheck to paycheck. So I’d like to know if this could be something serious enough to be evaluated? Better yet, what is this?