Afraid to sleep

I have never been "good" at sleep. Maybe it is because I am afraid that life is too short and I may miss something... maybe I invented that retroactivley because as long as I can remember I laid awake at night and needed a reason. This is not my problem it is just some background. I would love some insight into my "Panic Attacks". Sometimes before sleep (or during) I Start to think about my heart beating and how if I stop thinking about it my heart will stop. Of course this is stressful which increases my heart-rate (At this point i will be feeling my pulse). So I begin to believe I will Cause my own heart attack. I have a fiance- this has happened before him- and we share a bed. In these "attacks" I am terrified to tell him to wake him up. Yet I clutch my phone in case I need to call 911. Some nights pass this way and I 'wake-up" for work pretending I have slept till hours after I wake. I don't tell him right away because some nights this spirals into what I am told are night-terrors. My body is paralyzed but I hallucinate my love being evil terrorizing my paralyzed body (usaully hes just looking at me but I feel more fear than should ever exist) the I'll "wake up" but he goes from comforting me to the revealation that he's still evil (I'm still Dreaming) and this will happen two to twenty times).I promise it is not any sort of issuses with him.

This is really making me avoid sleep which i have never had enough of. If I take sleeping pills the dreams are there but it takes me longer to wake up from the "night terrors".
advice? or a similar story so I don't feel like I'm the only one paralysed.
Thanks for Taking the time to consider my situation

[MMahon]

Have you sought an medical help?
First off, you should get a good physical exam and blood work to check for any conditions that may be contributing to what you experience.  Get your thyroid and sugar levels checked.
Tell the doctor about the symptoms you detail here.  
They do sound like anxiety and panic attacks but you should rule out other things as well.
If I were you, I'd also ask your doctor to refer you to a psychiatrist for help in the treatment of anxiety and panic.  Good luck.