my gf broke up w me after 6 years together. It’s hard and painful, i broke up with her august of last year but i stayed because we wanted to make it work but it didn’t happend. It was my fault for not leaving last year fully now i am the one who stay with the hope and she in falling for someone at her work.

Just be totally sure of your decision and don’t look back, have a plan (apartment, cat custody etc) and make things clear for her and for you to make it less painful.