I am going to have agree. Go get it checked out, but you are young and most likely that doctor is going to tell you it may be anxiety. If it is, go learn about it and then confront it because it can fester and it can snowball and get out of control if we let it. Being proactive is very important with this in my opinion.
Sounds like you have health/heart anxiety which is really common among those of us with anxiety and panic disorders. Do yourself a huge favor and go have a complete cardio work up to rule out anything organically wrong with your heart. Then consider some therapy to figure out why you are so focused on your heart.
Getting drunk is not therapy I had in mind.................
Peace
Greenlydia