No need to apologize for not severing all ties for her. You want ties with her, that's your choice. You see what it got you - diddly-squat. You appear angry at FD's response, you also appear to be angry with your ex for standing you up. Take it from the Queen of Rage here .... I almost killed myself getting p.o.d when someone didn't give me the response I wanted. I was shooting myself in the foot by expecting everybody to say what I wanted them to say and do what I expected them to do.
Nobody is suggesting you be cold or nasty or indifferent to your ex. Just detach. I think it's okay that you wanted to check in with her to see how she was doing. She certainly didn't give a good cahoot what was going on with you by virtue of her not having the time to bother showing up.
Like it or not, as FD said, she was with her first and true love - booze. And self-torture can be having any expectations from an A. You don't have to get married and make babies with an A to get your heart stomped on.