Heart stopping?

I all of a sudden have this fear of my heart stopping. I have anxiety pretty bad, I worry about everything and look things up constantly. And I keep thinking theres something wrong with my heart and I feel like it's going to stop all the time. Like it beats really slow then fast and then skips beats. I went to the Dr and he said my heart is healthy. How do I stop thinking about my heart beat? It's so uncomfortable and it freaks me out :( I have GAD so it's really hard to control what I think, feel, and fear. No one seems to understand. Help please? Are there any breathing exercises I can do? I really just want this heart crap to go away so I can feel better. I don't want to keep focusing on how my heart rate is and I'm checking my blood pressure every hour. It's getting insane to the point where I'm scared to move and do things because I'm scared its just going to stop beating. Please help. And I also just got told I can have a heart attack!?!?! So now I'm REALLY FREAKING OUT. I was also taking Ativan for 3 weeks, and can't get anymore til a few more days (ER prescribed them temporarily, going to my first therapist on the 6th) And I'm going crazy without them because they helped tremendously. Just please give me some kind of advice on how to stop these crazy thoughts? The more I think about it the more it worsens and I can't calm down! And this is all anxiety right? I've been to the Dr and they found nothing. ALL tests came back normal. My heart is healthy but I fear there is something wrong still. Please help... :( :( :(

hello, try not to worry to much i feel the exact same way i constanly check my pulse and i have been put on propanolol which has caused me to have an irregular heart beat i have this constand pain in my dullness in my chest no pain but i am always aware of it when i get shooting pains thats when i start to worry but no this a panic attack peaks at 10 minutes so when u feel at your worst its only going to be for 10 mins right now whilst i am writing this i am thinking my heart is going to stop haha phycologicly i no that i am fine but my body doesnt seem to register ever!! i dont notice my chest heaviness when i am getting on with housework or keeping myself busy... my anxiety was alot lot worse and the fog is starting to slowly dissapear! i have bad days but i am starting to have alot more good days than bad just by keeping myself busy i hope this helps to know that u are not alone! my therapist asked how i feel and i said its like i have fallen down a black hole and there is another version of me at the top the one down the whole cant find her way back up but the one at the top is cheering me on motivating me.. i am half way up the hole now sounds silly ino but you will get there that much i am sure of!!