So, I recently made a new friend that I met through outpatient treatment (for depression). I got in a fight with her yesterday and basically ended our friendship. I'm not sure if I have overreacted but I have recently been very on guard and untrusting of others. 

To give a bit of a background, the first time we were supposed to hang out, I must have texted her 6 times that day asking when we were meeting and at what time, etc. She never got back to me and I started to worry. Around 10pm I texted a mutual friend and I asked her if she knew if she was ok. My friend responded, yeah shes fine shes been texting me. Immediately I was upset....you are clearly texting my friend and you haven't had a minute to respond to me while I've been waiting on you all day? You don't even have the courtesty to tell me that you can't make it? I confronted her and let her know that I knew she had been texting our mutual friend and that I am very disappointed that she left me hanging. Immediately, within seconds she responded saying she was sorry and had some sort of panic attack that had left her crippled for the rest of the night.

I forgave her and tried to be reasonable and realized that she was just going through something, although I knew that I would behave differently if I had been her. We started hanging out a lot, although I saw other red flags that started to kind of make my stomach churn. I realized she had let go of two of her best friends from the treatment center, saying that they were "too crazy" for her, even though she had spent every day with them in the past. I immediately became self conscious- Would she do this to me one day too? She also told me that she felt weird about meeting people in treatment. Granted, she has a past of being in the psych ward, paranoia, depression, severe panic attacks, etc, and she had gone to the treatment facility we met at multiple times, dropping out of school, etc.

So, a few days before NYE I had found out that one of my friends who I bought a ticket for to join me for a NYE event, couldnt make it. I had asked her if she would join me and she said, yeah I'll let you know! If I'm not doing anything with my fiances high school friends I will totally let you know. She also invited me to go hiking with her and her dog. When the day came to go hiking with her dog I reached out to her and didnt hear from her all day. On NYE I texted her asking if she could please let me know if she could join me for the event. I didn't hear anything from her, although she was present on Instagram all day. I saw one of her Instagram posts and congratulated her on her growh that year and said I was proud of her, but no response. I spent NYE alone in my apartment just waiting by my phone.

On New Years Day I wished her a happy near year, and then over the course of the next four days I had asked her if she was alright and if I had done something wrong to upset her. In total it was about five or so days before I heard from her, and it wasn't because she genuinely wanted to talk to me, it was because I sent her a final text expressing how upset and disappointed and abandoned I felt. How I saw that she was online but couldnt understand how she couldnt send me a courtesy text, especially involving NYE. She responded within seconds, defensively, after literally not responding at all for days. And her response was essentially that all of my assumptions about her were wrong and that she just "sucks at texting." And then stuck in that she had terrible PMS for a week and had been in bed shivering.

I admit that the things I told her as I grew more upset were pretty harsh. I told her that she is just like the rest of us from treatment and that I don't understand why she feels otherwise, and that it's hard for me to understand how she like creates these elaborate fantasies of like traveling to Spain together and like buys me Christmas gifts but then completely signs off. I told her that I don't treat people that way and that I try to be considerate especially when I know that they are waiting on me for something, and that I feel I deserve better. It is obvious to me that my abandonment issues were triggered (in the past when people ignored me for several days it became clear that they had no interest in talking to me again i.e. especially with men), but I was definitely hurt in this case. Especially when I reached out to her multiple times clearly distraught asking her if I had done anything wrong and if she was ok.

Did I overreact? Is she just kind of a shitty person? Friends who I had spoken to about the situation have validated that her behavior was not kind nor normal. I do feel badly about how I reacted (and have apologized to her since for being harsh although whats done is already done and we have both decided to go separate ways). Thoughts?