Severe anxiety for no reason, in my chest, especially at night. i have no idea what is causing it. what should i do?

I'd have eval 4 CBT: A good psych eval will lead to either some skill learning and/or medication. The combo is often best. You'll learn how to deal w/ things and perhaps have short term help from a calming drug. Best!

Psychotherapy: Ask yourself what environmental and interpersonal stressors you face during your waking hours, and whether or not you find yourself obsessing about them at night, which could be resulting in sleep loss. Consider going to a reputable psychotherapist for stress management therapy, and exploration of non-biochemical sources of anxiety.