That is PRECISELY what I experience! I had a panic attack completely out of the blue, and went to the ER thinking that I was having a heart attack. They couldn't find anything and recommended pursuing it with a doctor. Now it's almost two months later and I have gotten clean bloodwork, multiple good and identical EKGs, and a clean echocardiogram (I had been diagnosed with a valve problem as a child that they wanted to check - which this echo actually proved never existed!). I am still having chest pain (both heaviness/tightness and sharp, wrenching pains), and back pain daily, and had several more panic attacks after that first one. It is terrifying, but I keep reminding myself that I have to have faith that there is nothing wrong with me beyond the panic, and the panic can't hurt me.
I was doing much better, but my husband just left for training, and it came back with a vengeance. My doctor recommended wellbutrin to try and manage it a little longer (I also use xanax for the bad attacks). It hasn't kicked in yet, but, in the meantime, I have found that massage helps loosen up incredibly tight and painful back/chest/neck muscles - though they quickly tighten back up! I also followed someone else's suggestion to try covering my mouth and one nostril, and only breathe through one nostril. It seems counter-intuitive when you feel like you can't breathe, but it actually slows down my breathing, cuts down on the hyperventilation and helps me get the panic under control better. I had no idea I was hyperventilating, but that definitely exacerbates my symptoms. Sorry you're going through this too, but hopefully you can take some comfort in the fact you're not the only one!