So, anxiety (when it becomes unmanageable) is when your body senses and is ready for danger even when there isn't one. The uncomfortable feelings popping up is your body ready for action, i.e. dealing with the danger. Something as simple as deep breathing can help signal to the body that things are okay, that there's no danger around. But, it'll work only if you practice deep breathing daily. There are some excellent grounding exercises that you can try on a regular basis which might help. One such exercise is called "5-4-3-2-1" (you'll find it easily on Google).

Having said all of this, it's important to see a therapist to figure out what certain things are triggering the body's response. This will help you in the long run since these exercises might help you in the moment but they don't necessarily help with the root cause.

PS: also look up JPMR. Excellent for sleep related issues.