Chest pain left side near breast for a month now hurts back to aswell as arm feel it more when relaxing also have heavy heartbeat sometimes. im19 btw?

Chest xray: It is unlikely that you have angina/heart disease given your age and fact that this is constant and for a month. You don't mention breathing, cough, sputum, fevers. Have you had some sort of trauma? Is it positional, reproducible by pressing? You might have pneumonia, or inflammation/damage to major blood vessels or if it is superficial it is musculoskeletal and needs time to heal.