It's a way of showing you're very frustrated. The image is of you being so upset that you're banging your head on the wall because you can't think of anything else to do.
The head person.
Stay calm
An idiom is something that does not mean what the phrase says literally, so yes. You can't actually laugh your head off.
It means to get to business. Stop beating around the bush and do what needs to be done.
Nothing. Perhaps you are thinking of beating around the bush, which means to avoid the topic of conversation.
The idiom usually refers to a suggestion against which many arguments were presented.
"Dive in head first" is to rush into a situation without thinking.
To turn completely around and head back in the direction you came from.
Keep an idea in ones head to act on it later.
If used as an idiom, it usually means that you are confused about something. The image is of you scratching your head to try to think better.
A very severe headache, as if an imaginary axe is "splitting your head in two".
The idiom "a hot head" refers to someone who is easily angered or quick to become upset or frustrated. It implies that the person has a tendency to react emotionally or impulsively in challenging situations.