If someone in your life is toxic CUT THEM OFF AS SOON AS POSSIBLE. No matter how close you are or no matter how much you think you need them.
You have to do it for your own good, because once you're in their trap they'll eat every last bit of happiness and joy that you have until you're broken. To a point where it's nearly impossible to fix yourself.
Once they do that you're an easy target for them and they'll treat you terribly and use you then expect you to forgive them (in a lot or cases people forgive them). This cycle will only repeat.
Before it's to late, you have to cut them off.