I’ve noticed that many people try to fight the breakup by refusing to change their language.
They use words like "my boyfriend / girlfriend/ husband/ wife" instead of simply saying "my ex-". They use present tense instead of past tense when referring to the relationship, etc.
It’s not a huge thing in itself, but it’s a symptom of the refusal to let go.
This person is no longer your significant other. S/he is your ex-. And your relationship no longer is, it was.
As much as it hurts, you have to force yourself to make your language reflect the reality of the present.
Another linguistic slip is constantly using harsh, negative words like “nightmare", “debilitating", “unbearable."
Yes, I know it seems silly, but it’s really true: using words like these just prolongs your misery and continues your self-pity. Even when talking or writing just for yourself, try to use positive words to describe your situation: “overcome", “heal", “grow", “learn", etc.
The sooner you can do it, the quicker you will heal.