Normal EKG, but still don't feel right

This all started about a month ago. I started a new job that requires heavy lifting. One day I don't think I drank enough water because on the way home my hands got really tense where I couldn't move them, I was breathing heavy and felt like I was going to die. I got home and drank water and my hands loosened up, but I started having chest pains shortly after this and thought "I'm going to have a heartattack". I've been to the med center twice and they did 2 EKGS, both were normal. I've been checking my blood pressure at the local pharmacy and its been normal. I still don't feel right. Sometimes I feel like I'm dizzy, but I can't tell. The center of my chest was very tender today and it had me worried, and halfway through my workday my feet started sweating profusely. I felt a sense of doom. I do smoke and drink on the weekends but I've cut back. Could I have damaged my heart when I was so dehydrated and my hands locked up?. I'm not feeling tightness in my chest anymore, but sometimes I'll wake up in the morning with a heavy heartbeat. Someitmes I feel tiny bits of numbness in my left and right arms and legs. And every once in a while when I'm stressed I will have random chest pains, sometimes sharp but sometimes a pressure Could this just be in my head? Could there be a clot somewhere else? Any input would be appreciated.