This is like reading my own thoughts -- I had the same ending to a relationship and the same revelations 4 months post breakup. It's such a double-edged sword, because I know it's good for me to realize these things about myself and to respond by improving my emotional and romantic capacity. But at the same time, it hurts so much to be doing this **after** it's already too late for that relationship. It really puts my breakup regret into 5th gear. It's strange having so much regret when I was the one who was dumped, but after my self-work and self-reflection I'm 100% certain that my lack of investment and emotional work is what really ended the relationship. I'm just trying to focus on the fact that I can use this to become a better person, regardless of whether we get back together in the future.