A girl like this will see threats where they doesn’t really exist. She will be jealous of every woman who enters your life, and she won’t trust you when you say someone is just a friend or a colleague.
She will always make problems where they don’t exist, and you won’t be able to convince her that you only love her and that you are not interested in other women.
She will be suspicious the whole time, and that will bring your relationship to the breaking point in the end.