It is great that you have identified some things that you want / need to improve in yourself.
Is there anything that you can think of that your W has specifically said she doesn't like about you, even if it is from a few years back and you haven't made any improvements in those areas.
It is possible that our spouses will make up excuses or reasons, so if you ask her, she may just give you any old reason. I would be up to you to determine how valid those might be, but even so, if those things are improved, then they are one less thing to use as an excuse.
What were some of the arguments that you had, as mentioned above? What were they about? This might give some insight to your W's frustrations in the M.
