I forgot to say, that I hope you said something to your best friend who was also friends with the others who bashed you and added wood to the fire. My best friends wouldn't join and trash me with other people who do. If they did disgree or didn't like something about me, they would either accept it or they would say something to me to my face, with the hope that I better myself, or at least think about it and decide for myself what I want to keep in character. Then, it is their choice and mine, whether we stay friends or we can't abide by whatever it is that is causing concern.
As we get older and move in life, it is rare for things to stay the same and we change or "evolve," as a friend of mine would say. We also make mistakes.
You are thoughtful to wonder what happened and ask questions.Most people are a mixed bag and complex, so just as it wouldn't be realistic to think something like this means you are a "war freak or more" or evil incarnate. I would just work on learning from it, taking reasonable action to try to resolve things as it is within my ability to do, and take the reasonable consequences. If it turns into a hard and complicated situation than what can be handled, let it lie. It was one sentence, and it doesn't have to have more power than it deserves. I think what happened on your own 18th birthday got carried over and influenced what you said in hers.
I'm not excusing the bashers and the bullies. I just think you can take a higher ground and be the person you would like them to be and ask that from yourself. It sounds like you have an issue about support and boundaries with your friend. That is something you can discuss with her privately, but I, personally, would think and sort through things in my own mind to make it a little more clearer to myself what it is I have concerns about and what I need or would like to make things better, and not keep dragging it as if it was a dead horse.
I am just going to zero in on your best friend's party. That particular girl was a guest at your best friend's party, and I am guessing your bf invited her. I don't know what happened during the "scene" you mentioned, but the words you said, that a "normal best friend" would say was pretty loaded, and I can see why she cried, because she was put into a position in public at her own birthday party, where she was called out to pick and choose who her friends "should" be by one of her invited guests. I think you know that. If your bf didn't want the other girl to be there, she would have not invited her or had her stay in her party. I think it would have been better if you stopped after "Thank you for being real." The additional comment was basicallly your opinion, and it was incendiary and a bit of a put down, probalby aimed at the people who were bashing you. If I was there, I would have been insulted, and I would have been a bystander. I wouldn't know if I was a viewed as a "true friend" or what. There was a chip on your shoulder when that was said, and basically, it was like asking someone to knock it down and start a fight.
I don't know about you, but I wouldn't view a birthday party as a place to make issues over things, especially with the other guests or put the host in the uncomfortable position of being in the middle of it. If you couldn't tolerate the other guests, you could have just made an excuse and left. If the other guests are not behaving well, don't join into the rudeness. That's what I would do. There are friends and famiy that my friends have that I don't particularly like. There are even people who say some pretty terrible gossip or comments to me. I work and live around people that I wouldn't really want to have as friends, but I can co-exist with them. If they say something unkind or vicious, I ignore them, or if it was absolutely ridiculous, I can laugh about it.
We can't like everyone in the world, because we are all so different and we all have are own kinds of issues, desires and needs. If we were perfect creatures, we wouldn't have disputes or wars. The best thing we can do is have a neutral territory, be diplomatic, and put aside our differences. If one person can't do that, don't feed into her issue, be the better person and be courteous, not reactive. leave the past behind and move on. Her birthday party was neutral territory. When other people say pointed or snide remarks about another and it happens to be you, you let it go or walk away and move to another group or person that is friendlier. When you give a speech at a freind's party, it is usual to stick to saying something nice about the person who invited you, and leave all the issues and choice words and weapons outside the door.
If you care about your friend's feelings, or others, then I think you know what to do. Since this isn't really a 2 way dialogue, I would make an apology. I've said things that I regretted or that I didn't see as a thing or statement that would hurt another, but when I realize what effect it had or that I know right after I said it, that it was the wrong thing to say, I make amends, and I hope the other person or others, would be willing to forgive me. That would be their choice. If they have something to say about it, then listen to what they have to say, and try to understand where they are coming from. Understanding is a 2 way shared conversation.
If you are being cyberbullied on Twitter, then, I would either close the account and let Twitter know that is happening or I wouldn't even look at what they have to say if it bothered me that much. They can't bully you when you close the door on them.