to become unable to act in a calm or sensible way
This basically means that you should not go crazy about something that is trivial (not very important).
When you are excited, someone might tell you this to get you to calm down.
It could also mean that you are getting overexcited about something. You may have gotten praise for something, like "That was great!" and gone completely overboard on what you perceive it to mean. Like over-analyzing.
Making it more than what it really is.
To "lose your head" is to become out of control, as in very angry or very frightened. "Don't lose your head" would mean "Don't lose control of your emotions."
The head person.
The idiom "to lose one's head" means to panic or become overwhelmed in a situation. There isn't a specific sentence for this idiom as it is used in various contexts. However, an example sentence could be "During the emergency, she lost her head and couldn't think clearly."
to be in dept , to owe money or to lose money
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.
A person needs to lose weight.
Lose your temper.
"Dive in head first" is to rush into a situation without thinking.
The idiom, "You lost your marbles," means that you've gone crazy.
It means to feel that there is no way to go on and you just want to give up.
This isn't an idiom. It means just what it seems to mean. Something is enough so that even a saint would lose patience with it.
To turn completely around and head back in the direction you came from.