Sparky,I am sorry to read of your break-up and even when you know it is likely to happen it does not make you feel any better when it actually occurs. I suspect there was nothing you could have done to stop this event.
I have been in your position more than once and the feelings you are having about your past actions are most likely warped and incorrect as most of us are good at blaming ourselves for "bad luck". We believe we could have done something to have prevented someone from leaving us and even go so far as to think we can make ourselves more lovable.
I know this is hard to understand - you will feel better with time so try not to knee jerk and make any rash decisions at this time in your life. Give yourself time - let out your feelings of sadness.
I suggest you read Dr. Phil's Life Strategies and then Eckhart Tolle The Power of Now It is not helpful to you to hate yourself you so try things you have always wanted to do............. You have an opportunity in front of you. You can choose to live life to the fullest knowing that nothing is permanent no matter how much we would like it to be.
"Life is a succession of moments. To live each one is to succeed." Coria Kent