In my case, I cared a lot and I still care about him...
But the relationship was killing me inside, I was so tired of the constant chaos, worrying about his drinking, the irritable mood swings, the rude and inconsiderate behavior and the verbal abuse. It took a real toll on me as I found myself becoming increasingly anxious, angry and unproductive at work.
Even today I still love him and there are parts of the relationship I miss terribly but I don't miss walking around on eggshells, getting yelled at, feeling ignored, unloved and unheard.
Why do you wan to stay in a situation that makes you miserable and is making you sick and unhealthy? Being alone is scary, I know.... but not having to deal with someone else's drinking and anger is a blessing.