One thing that helped me was to make a list of the positives and negatives. Seems silly now, but I ended up having to add weights to increase the importance of the positives to have them out-weigh the negatives.
There were a lot of negatives it turned out.
Other people have used lists like this to remind themselves that their former partner actually was a jerk and pull it out to re-read whenever they feel themselves slip.
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells