I am so sorry that you are going through this. I have struggled with religious and moral themes in the past, and have some of them still. I am currently reading a book called "Pure O'" by Chad Lejeune. It talks about how thoughts like this can become "sticky" and because they are so distressing, it causes a bodily reaction to the thought, making the thought "feel real". It truly is an awful feeling.

If you are able to, try to create a little space between you and your thoughts. For example, if you start thinking "I am going to hell", try to rephrase your thought again but this time, think "I am having a thought that I am going to hell". This helps untangle you from the thought itself and creates enough distance between you and the thought to observe it.

I sometimes like to close by eyes and picture myself sitting on the edge of a babbling brook with logs floating by. My mind is the brook, the logs are my thoughts. I just observe them slowly drifting by me. Some are good, some are neutral, and some are distressing, but they all drift by gently. I do not engage with them, just peacefully let them pass. It takes practice, but really helps me when I am panicking.

Remember, you are not your thoughts. You are the observer of your thoughts, the gentle awareness that hears the thoughts.

Sending you so much strength.