May I Ask a Question?

It looks right but after the what use either a ? or !

"Don't leave me hanging" is a common phrase but it's hard to tell if you're using it correctly without context. You can write "What!?" to show that it's a very expressive/loud/emphasized question, but this is would normally only be used in informal writing.

I just learned something new because of this post. There's a non-standard (not grammatically correct) punctuation mark called the Interrobang that combines the question mark and exclamation mark. More here: http://en.wikipedia.org/wiki/Interrobang