Translation of "Dumbfounded" in Spanish

- I am dumbfounded.
- I'm dumbfounded.

Yo estoy estupefacto.

Tom is dumbfounded.

Tom está anonadado.

I was totally dumbfounded.

Estaba completamente consternado.

- Tom looks dumbfounded.
- Tom looks nonplussed.

Tom parece perplejo.

When I heard it, I was dumbfounded.

Cuando lo oí, me quedé perplejo.