buried alive in one's own mind

To me, the worst part about the mental pain of anxiety and depression is not being able to take a pill to make it go away, or not being able to go to a doctor or the emergency room for relief, as one might with a terrible headache or a broken bone.

I've had times when I felt so mentally bad that I didn't know how I would make it through the next 30 minutes, much less the rest of a day...times where I felt so mentally trapped that I thought there was no way out, other than to suffer interminably through it or to commit suicide.

It's times like the above that have made me think of this way of being trapped in one's own head as akin to being buried alive, except, again, in one's own mind...there's no way out.