Yes, I have experienced this too.

Recently. I posted about 'flooding' after uncovering a horrible trauma. I think overwhelmed is on a continuum with flooding....

But you know, after the intensity died down, I felt similar, and dark and depressed. After that, I felt better than I had in a long time. The trauma unearthed explained so much in my life! Now it's dissipated, and I feel much 'lighter". Better overall.

I hope you feel better soon.