It used to happen when i had panic attacks. last time was like 2 months ago.
My thoughts would accelerate ALOT! Until they became so loud that i couldn't hear anything around me for them basicy.
I know that they came from me and it all was in my head, the duration is like 30-90 secs.
it just felt like 10 thoughts at the same time, rather loud in my head, completely overwhelming. I can't make sence of what they are saying/thinking, it's just like white noise in the form of thoughts.

When i write racing thought i mean it like they "move" fast and i get multible thoughts at the same time-ish. If that makes sence...