I play drums for a band. There have been lots of nights after a gig, that I have been very tired, felt like I might fall over, and have felt like I might vomit. But after the last gig I became a little worried. We were only at the end of the second set, and I felt like I was going to fall over. During our break (about 20-30 minutes), I felt like my heart was just pounding. As I got up to go back on stage, I felt like I might vomitt. I didn't, and I pushed myself to make it to the end of the show. The difference this time compared to the other gigs, was that I had pressure, or tightness on my chest from Saturday night, until Wednesday morning. Do you have any ideas at to what might be the problem.