I Am Going Through a Break-up

Not sure where to start this with, or where. Guess I will just start at the top. For the last two years I have been dating well seeing this wonderful girl. Having just got out of a marriage, I was at the time mostly just looking for someone to talk too. Nothing more past that, well that was not the case here. Feeling developed and well things happened. Sadly, I am someone who has a lot of fears, and worries, and to cover a lot of that up I overload myself with all kinds of work, and drive, schooling, just all kind of things. I created a 3 page list of things I wanted to get down this year on the 1st of Jan. Funny thing one them was not to overload myself. Well sadly it was just the opposite, and sadly it well cost me a relationship, but more importantly, I hurt someone and put them in place of sadness and aloneness for the better part of a year. I did not listen like I should've, promised change but it was just minor change, and well here I am. Sad and alone myself. And angry at myself for my actions. This is the 2nd time I have done this, it's like I get into this routine of things and well I am locked in. I just am feeling lost, and angry, sad. What in the hell, did I do?