Put a gun to (someone's) head informal
The verb "hold" can substitute for the verb "put".
If a person "puts a gun to someone's head", he/she puts pressure on someone, forces them to do something they don't want to do by using threats or menaces (not necessarily with a gun in literal meaning).
Actually, nobody put a gun to your head and forced you to accept this offer. You could turn it down in the first place.
If she had not put a gun to my head, I wouldn't have obeyed her unconditionally.
He went to the party in a bad mood as if someone had put a gun to his head and forced him to attend.
The verb "put" should be conjugated according to its tense.
This hyperbolic expression dates from the first half of the 1900s.