I've had times like you describe. I've called 911 because I couldn't stand up without completely passing out. Shaking so bad it looks like I'm having a violent seizure. They made me wear a heart monitor for 3 days after. Told me it's just anxiety in the end. Anxiety will do crazy things when you feed the thoughts. Anytime I have anxiety and start a thought with "what if", I stop it. What ifs cause a lot of stress over things that will probably never happen.

The chest pains are the worst. I've learned to never check my pulse and tell myself that it's just muscles spasming in my chest. Not sure how old you are or where you're from, but CBD oil has definitely helped me.