Hello, I Experience Chest Pain From Time To Time, And

hello, I experience chest pain from time to time, and just a moment ago it happened but only for about 2 seconds and went away. i have had numerous chest xrays and ekgs. i get panic attacks that send me to the emergency room, which lead to EKG. they always turn out fine and abolutely nothing wrong with my heart (doctors say). i take 30mg oxycodone 4x a day, and 1mg klonopin 4x a day. please help me understand why im having chest pain. i get dizzy, stomach and back pain as well. anything is appreciated...thank you... i am a 33 year old male