To panic, you have to be thinking fearful thoughts. That sensation in your body is the fight or flight response. It's a very physical response to an
imagined threat.
This sensation feels so much worse at night because everything is quiet and there's nothing to distract the mind away from it. Also, we feel alone. But it's no more dangerous at night than it is in the daytime. It's actually your body working as it should do, it's just that your brain doesn't know the difference between what's real and what's not..
Don't block the thoughts. What's suppressed will be expressed in other ways - and that means anxiety. Allow the thoughts to come. They can't hurt you. Nor can the fight or flight response because that's there to protect you. Just observe the thoughts for what they are and challenge your thinking/reframe the thoughts. The deep breathing - well done you by the way
- will actively turn OFF the fight or flight response but
only as long as you stop fearing your thoughts! Fear will just keep triggering the fight or flight, it's like flicking a switch on and off!
It's not harming you. It's just a sensation that feels unpleasant as most anxiety symptoms do. The more you focus on a symptom, the more you will get it because of the stress hormones which are released into your system every time you fear the sensation. When we are excited, we get sensations in our body - just the same. It's adrenalin.
Have a look into EFT (tapping) and when you get these sensations you can tap and say to yourself, 'This sensation feels unpleasant but I know what it is and that it can't hurt me'. By the time you've done a few rounds of tapping and deep breathing - you will have clamed things down.
A good podcast to teach you how to do this is Anxiety Slayer. Check it out Mrs R. X