I know exactly what that's like. I used to be absolutely obsessed with my heartbeat! I worried it was irregular, too slow, too fast, too strong, too weak, everything!
What works for me is distraction. Try going for a walk, singing, watching a good movie, or putting on headphones with a song you really like playing.
Also, I'd avoid the alcohol all together. Alcohol can make your heart beat irregularly (not dangerous usually) but that can really trigger panic.
Hang in there :)