It appears that you had quite the weekend, a weekend to learn how to rely on yourself and how to deal w/the many obstacles that have crossed your path.
I can understand the anger and annoyance, but maybe it's time to take a look at your situation, since your mother has indicated that she can't babysit anymore last minute. Think about it, how many times have you called her last minute? Your mother may have had plans in the past and had to change them to take care of your little one. Maybe it's time to put a back up plan in place in case you need someone last minute and no one else is available. Not smacking your hands or being harsh, but maybe people are starting to feel a bit "used" at the last minute and have to change their plans to accommodate your needs. I'm glad someone stepped up to the plate to take care of your little one. Sometimes God works in mysterious ways.
One more lesson for you....keep your expectations at zero or very low, especially w/your h. If it wasn't his weekend to have your daughter, then you shouldn't have expected him to be in town or to notify you that he was out of town, if you are separated. As a general courtesy rule, yes, it would have been nice to be informed, but he didn't...however, he had his phone so that you could call him in case of an emergency.
Yes, you are angry and that's one of the stages of grief. You are going to be angry at every little thing for quite a while...but you'll need to rein that anger in when dealing w/others. As for the insurance company switch, when searching for a therapist, call around and ask if they are solution based. If they aren't...then you should continue looking around. Some therapists are very good and then, they are others that figure since you are separated, the life is going south, per se and a divorce will come. Some don't recognize MLC at all and others do. Ask questions before you make an appointment, if you get the opportunity. Do a search of the practice and see what's out there on the internet about said practice.
I'm going to ask a question that may anger you...but the two ladies that didn't attend the Saturday evening meet up...have you been discussing your situation w/them? Have you been complaining to them? If so, they may have opted not to meet up because they didn't want to hear about the situation again. If that is the case, it's best to choose one friend to lean on to discuss your situation.
Take a good, long, hard look in the mirror...you are not a victim...you need to get stronger and more independent and yes, you are a survivor.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.