We can't always trust our emotions. Often we have to put up with a little bit of momentary pain in favor of what's best for us over the long term.
That's the hardest thing for the alcoholic, too. We know we should quit, so why don't we? It's hard and it's painful. The withdrawal sucks, and then we gotta deal with all the emotions that arise without the alcohol to numb them, and they can be excruciating... depression, anxiety, guilt, shame, anger.. and nothing seems to alleviate them. It's a long process to figure out how to cope and overcome these in the absence of alcohol.
But I personally keep pressing on because I know that this is temporary.
Leaving a person who you once loved is very hard, too, no matter how much they might have hurt you. But because it's hard to stop, should the alcoholic keep drinking? Should you stay in a relationship that hurts you? No.