Hi Kitty.
I have experienced something very similar to that, and to me it didn't seem like conventional anxiety or a panic attack. It was not a purely depressive mood either. If anything it could be described as agitated depression, but more inward agitation than outward. Perceptions got very mixed up, and auditory and visual stimuli became very distorted, while my mind would play back thoughts and variations so dominantly it was almost as if a dream had taken over my interactions with other people - where the chaos of the dream was louder in my mind than what people around me were actually saying or doing.

The best my therapist and psychiatrist could come up with was "maybe it was some sort of panic attack" - but that just doesn't ring true to me because there was nothing I could associate any threat with - nothing to panic about, except the extremely distressing experience itself.

I felt I was walking on the razor edge of psychosis.
Fortunately it didn't last very long, and I was back to my normal BP mood swings the next day. (I've been on Sodium Valproate and Lithium which may have helped keep me out of the really deep water).