While you may still want to find a new sponsor, expecting one person to be on call for you 24/7 is not reasonable. If that is what you expect, I would predict that you will be disappointed many times in the future.
I think this is a key point, because if you chose to think that your sponsor was unfair and let you down because she would not come running to support you in emotional crisis--that will be your excuse to drink and use in future.
Being angry is fine, but understand that the anger is YOURS. If you pick yourself up and call other friends--then you will be setting yourself on a good path to recovery.
Yes, it would be great if your sponsor was there, but she said that she was helping someone else! Why are you more important than this other person? This is just how life is. There will always be problems and if you can learn to roll with them--even in the midst of your own crisis!--well then you will do fine when the going gets really tough.