Best cure for bad heartburn after hard workout?

So I really over did it yesterday at the gym. I did an hour of various work outs, mostly cardio, but I ended my session with some sit ups and crunches. I felt nauseous while I was working out (I'm pretty out of shape) but I figured I would feel better once I stopped. I don't feel better. I have terrible heartburn and pain in my stomach (right under the sternum) which has been persistent for about 36 hours now. I have been taking Dramamine for the nausea and to help me sleep, but I've tried Tums and Maalox for the heartburn itself with no relief. Is there anything that I can take to help calm down my heartburn and to provide immediate relief?