Will I always cringe at the past? Probably.
Do the feelings of guilt go away if I succeed in quitting? YES, YES, YES
For me the biggest benefit of quitting was waking up in the morning without feeling self-loathing and self-reproach. It's the most addictive part of being sober.
Imagine yourself waking, knowing you had spent quality, nurturing time with your children the previous day. It may not kill all guilt about the past but it goes a hell of a long way.