Having recently gotten out of what I can perhaps best describe as an abusive relationship, I have found making a timeline of events to be extremely fulfilling and liberating.
In any bad relationship, there is going to be some tendency for self-blame, guilt, polarization, and confusion. Laying out a timeline of as much as you can remember lets you take a good objective look at things. I'm not sure I'd reccomend this continuously in a relationship, because it would be too much likescore-keeping, but keeping a diary you could look back on would help. You will find that things you were feeling guilty about were entirely in line, and you will find other things that it would have been good to handle differently. You might still feel guilty, but it will be a realistic guilt about a problem that is actually manageable. Likewise, you will see ways in which the other person was not as bad as you had been feeling they were, and other, perhaps more fundamental problems.
Hey, it's worth a shot.