Many people are already knee deep in a pre-marital relationship before they realize they need to get out of it. I am heartbroken by the stories people told me about the difficult situations they're in. They want to get out, but they can't simply do it.
Often times, it is not a simple black and white answer such as "Break up right now! It's haram!" Getting out of such a relationship is harder than ripping a band aid.
Having said that, I want to advice myself and everyone out there: Please, please, please, take care of yourself.
There is hikmah in what Allah made impermissible. We might not see it now, but we might see it later. The thing is, I fear that "later" might be too late.
"And do not APPROACH zina. Indeed, it is ever an immorality and is evil as a way." (Surah al-Isra, Ayah 32)
Take heed of this message. NOBODY is exempted from it. Nobody, not even married people.
Prevention is better - and less painful - than cure.
Indeed, Allah knows best.