Anxiety Support Group
Anxiety is a physical condition marked by intense and persistent feelings of distress, fear, angst or dread. General anxiety caused by routine day-to-day stresses usually passes quickly and is experienced by almost everyone at one time or another. However, such feelings that linger over time and are very difficult to cope with, and which lack a clear cause, may indicate...

The first part of your post could describe what I call my "Acute Anxiety Attacks." They are harsh and sudden. On my good days, I can ply therapy tools on the acute attacks and head off a whole lot of pain.
When they begin escalating in frequency and longevity, I call them, "Episodes." The anxiety episodes are a living Hell and much, much harder to therapute.
So it feels inside my own skin, in my own words.
Gentle support while you figure what ^it^ is in your case. Welcome aboard.