Hello, I have weird this happening already 1 year more or less. I have GAD and PA (now under control). When i just falling asleep seconds after i jumping out of my sleep with shortness of breath kind of choking my heath beats faster and I am panicking little bit. I am graping my pulse and checking whether i am dying or what is happening with me :( This can happen also during my nap in the midday. This thing doesn't happening every night also this happening only seconds after i fall a sleep and never in the middle of the night or something. Tonight i had 5 episodes in a row like you falling asleep waking up and again. Then i took little bit of Bromazepam and after 30 minutes i slept like a rock. Bromazepam is always helping. I see that this thing happening when i started to tapper from Seroxat 20 mg now i am on 5 mg. Anyone similar experience? It is so scary :(
yes this happens to a lot of people with anxiety. You’re not going to die it’s just a reaction some people have.
One thing you can do is to learn proper breathing technique for anxiety to completely calm everything down. YouTube has some great short breathing meditations that will help.
i particularly like one called don’t panic. It is in black letters with a white back ground . you first search for one called stop panic attacks now, and then you scroll down to the one called don’t panic.
it works every time for me and brings my heart rate down in my breathing under control! 
yes,the same i feel