You need to consult a psychiatrist, not us. As far as I know, suboxone is an addictive drug, and stopping abruptly as you did sent you into withdrawal most likely. Not a good idea to do when you were suffering from an anxiety attack. As for using the two together, you need to talk to a professional. One anxiety attack does not a disorder make. Chronic ones do. Opiates are calming as long as you keep taking them, and when you stop, the calming effect stops and your body also goes into a physical withdrawal. By the way, if the docs found nothing wrong with your heart, you may think your heart was racing but it might not have actually been racing. Anxiety attacks can feel like it is but it doesn't mean it is in fact doing that. Mostly it's your thoughts racing and your adrenal gland racing, not necessarily any other part of you. Depends on the person. What you don't want to do is rely on the ER for treatment. That's for emergencies, but when you leave, you have to find a regular professional to get regular treatment. ER folks are just trying to deal with the emergency and move on to the next patient. Hope you find your answer.