Putting somebody on a pedestal

It seems that I put my partner of a pedestal.
And this is the reason why it feels so hard to break up with him. When I put on paper what I think about him I’m surprised about who he is, which is not even close with whom he is in real life and the way he treats me and people in general.
How do I get to take him off that pedestal?
I know you will probably say with my thoughts but I either did not practice them much either I did not pick the right thoughts to practice.
Do you have any suggestions?

Thank you:)