I have normal blood work, (CBC, CMP) how would I know I have angina or something related to heart? Scared because I get chest discomfort symptoms. I'm 19.

Unlikely heart. Your swallow tube enters the stomach just behind & a little lower than the heart. Stomach acid often backs up near that point because there is no valve, just a fold of tissue held closed by weak muscles. Caffeine, nicotine, carbonated fluids, laying down after feeds, all make it hard to keep this closed. This can trigger chronic gnawing or episodic pain. Try some Tums or change your diet. .
Detailed history. It sounds like you have already had some testing, although basic blood tests don’t tell much about the heart. These little text boxes are not big enough to go through all the details, which is what a doctor would need to be able to help. With pain which concerns you, you might consider a second opinion inbox consult here on HealthTap where you can share the records of your tests for review. .