She may have ended the affair 5 years ago but your dday was only a year ago. You are asking too much of yourself.
It's generally said to take 2-5 years to heal from this. You don't get to pick a timeframe, it just happens organically if the conditions for R are right.
I know you are probably tired of feeling like this but you have to go THROUGH it, you can't just move past it. Be kinder and gentler with yourself.
TT for 6 months
Unremorseful for 3.5 years
Delay is the deadliest form of denial. - C. Northcote Parkinson
Your standards aren't up for negotiation just because he/she can't meet them.