Dumbfangled

To be confounded and confused at some new information. When you hear something astounding and baffling and can't immediately process it.

When I heard Rihanna might be getting back together with Chris Brown I was dumbfangled. I couldn't even figure out what to say for like a minute.

This new operating system has me dumbfangled. Where is everything?! I don't know what to do!