Idk how do you call this emotion......betrayal?...And how do you get over t?

Hello to whoever is reading this! I just wanted some advice on something that happened to me about a week and a half ago.... So basically I went to Anime NYC for the first time,and if I had to rank it out of all conventions I went to....it would rank number 1 as the worst.... Not the anime convention itself, it was extremely fun....but what I experienced from it made it extremely bad... I am not a fan of going to places or outings when school is like practically in session, but my so called "best friend" kept on nagging me to come with her because she didn't want to be alone, so I finally gave in, buying the weekend ticket, cosplay, and materials to make the prop for my cosplay.....which was extremely expensive. It took me all week and the night before to finish everything I needed for the cosplay, and I was so happy. I haven't seen my "best friend" in a few moths because we go to different colleges, so hanging out with her was going to brighten up my already dull and depressed life. I get to the anime convention....I call my best friend, asking where is she? She answered and told me she was at "this location", and I told her to wait for a bit as I go into the bathroom to change into my complete cosplay. She agreed to that, and it only took me 10 minutes to change completely, and once I came out....that's when this shitstorm started. I called my "best friend".....no response. I called her a second time.....no response still. At first I thought maybe the place is too loud, (and it was with so many things going on at the same time) so I texted her. She did respond. I asked her, where is she within the building? She said "Oh I'm outside!" .....It took me a few nanoseconds to process this and I asked her where specifically, she did not reply. She didn't reply for an hour almost. I called her again, no response. I called her 3 more times....still no response! At this point I was getting anxious, angry, and upset. In my mind, I was starting to think 'I came here for no reason! I spent time and money for absolutely nothing! Why would my best friend do this to me!?!?!' and almost everything negative that could pop into my mind. And then my mind told me to go on her instagram since my best friend does use instagram a lot. So I did. My heart dropped the moment I did. My "best friend" was hanging out with her other 2 friends, and taking pictures of other cosplayers. I was at the convention for 5 hours.....and we never met up. I wasn't planning on making this day to be ruined by the likes of her....so I just went to panels, and the vendors room, looking at all of the interesting and fun stuff the con had to offer. When I was about to leave, I texted her one more time, and I asked, where were you the whole time? I was looking for you for about 2-3 hours. And I kid you not...she responded, "I was in the vendors room the whole time!" I am not even mad that she spent the day with her 2 other friends. I am not mad she told me she was in the vendors room the whole time. I am not mad she invited me and I spent so much money for this event. I am upset that my so called best friend, invited me to an event, where we could hang out together, never ever really showed interest in coming to find me, or try to find me. She just ignored me and casted me aside..... I am already an introverted, overly sensitive person. And seeing that the person I call best friend do something like this to me...I felt and still feel humiliated and betrayed. So....how do I get rid of this emotion?

Go to an anime convention with me. I make meetups and group events at anime cons all the time. Instead of going with 1 friend, go in a group. If 1 flakes, the rest are still there to have fun

On a serious note, don't dwell on it. It's over. You can't change what she did nor can you change the outcome. Fuck it. Fuck her. Keep it moving. Head up high, Rose.

Uh... Hold a grudge for about two months, then try to forgive her. Honestly though, I've seen too many good cons get ruined by con drama. I don't normally recommend this, but when it comes to con drama, it's best to try to put it past you. As for betrayal in general, that's a tough one to just get over so easily. Even after you forgive them.

Because I'm a pisces. We hold grudges for 2 months at most. And in this case, she is allowed to be a little angry at her friend. Within reason.

I agree she can and should be mad at her frosted flake friend, I just don't get the timer. Fuck forgiving her. Drop her like a bad habit. I'm not saying stay mad either. You'll get over it but you don't have to forgive her for shit

I must thank you for your advice, both of you! I am mad, but my feelings of sadness and ashamed has taken over me a bit. Just for the sole reason that we have been through so much together. I just wasn't expecting that from her. And to add onto this, my other friend who was introduced to me by my "best friend" told me that she was nothing but trouble. Let's call my "best friend"....Kat. This just happened to me a few minutes ago as I was talking to my friend. She told me that she and Kat had a conversation about how they barely talk anymore and so Kat responded "You have to contact me! I have a large friend group and I can remember all of you guys unless you contact me!" Just typing and reading this hurts me.