What to do if i am 17 years old and have anxiety bad and worry about my heart and dying. could that be a reason why my heart bothers me?

Panic Attacks?: Panic attacks are characterized by extreme symptoms of anxiety (hearth palpitations, dizziness, shortness of breath, etc.) that are mentally accompanied with a feeling of doom, and interpreted as a "heart attack" "I'm going to die". A physician should rule out any medical conditions first. If no other medical cause is found psychotherapy with Cognitive Behavioral treatment helps with the anxiety.