Your urge to protect someone is admirable, but you need to realize that there's a chance you could get dragged down with them. It's not too late to distance yourself from the mess they have created: and you might want to do it. Sure, it might make you feel guilty, but do you think that this person would do the same for you? It's time to stop making things so hard for yourself, and start admitting that the easy way out isn't always the wrong way out.