Hello! Thank you for asking on HCM! Facing your actual complains, I would recommend you to visit an ER service in your area, for a medical check up. First of all, an ischemic heart disorder should be ruled in/out, as that racing and hurting heart associated with left arm numbness are primarily suggestive of such a suspicion. A careful physical exam, resting ECG and some blood tests (cardiac enzymes) will clarify this point. If heart issues are excluded then a further differential diagnosis should be carry on, including potential drugs effects, or any other food related implications (like tyramine-rich cheese, or other spicy compounds, etc). Meanwhile, I would recommend you hereinafter to follow a healthy life style, no illicit drugs, sufficient sleeping, and of course a healthy diet (I would encourage Mediterranean diet). Hope to have been helpful to you! Greetings! Dr. Iliri