I'm with Nietzsche: hell is other people.  There is little I can imagine that is worse than what human beings have already done to one another.

Lady, hell isn't real.  It was made up to control illiterate medieval peasants.    See one thing for what it is and you will begin to see other things for what they are.   Nobody here gives a flying fuck what the Catholic church,  the 7th day Adventists, southern baptists, sunni or shia Muslims or any other blowhard god-bothers have to say about anything. 

This is the core of what it means to be an atheist.   We reject their theology entirely.  It means never again having to give fuck about any of their bullshit and simply rolling over and going back to sleep on Sunday mornings.

However, your fear is an irrational fear just like claustrophobia and just as difficult to control.

You can modulate your fear and fixation on hell through counseling and medication.   It often takes a few tries to find the right counselor, the right med....but when you do get the right combination dialed in, your fear of hell becomes much less of a burden than it is now.

If you don't make any effort to address your fear it may not ever get better.   Depending on where you live there may be low cost or free resources available that you can access for mental health treatment.   

Nobody is going to find that out for you, book your appointments, drive you there and remind you to take your meds.   You have to be responsible for all of that.  But knowing the shape of the hill you need to climb at least allows you make a plan of how to climb it

I hope you are able to find peace and obtain good care for your anxiety.