Tight chest, heart pound so fast, left arm feels tingling, dizzy, cold hand and feet, sweating, suddenly stiff at neck & shoulder. Heart attack or anxiety?

Uncertain. You are a 30 year old female - don't know if you have any risk factors for a heart attack. However, if you have never had a medical workup and had medical causes ruled out than having it assessed is prudent. It may be a panic attack but we can't diagnose it.