I think that if you try to keep the moral high ground and say all nice and positive things to her during your breakup message, you'll regret it after the fact.
You speak wise words like
At the end of the day, she is a weak little girl and I am a man.
A man does not worry about being spiteful towards someone without power over him. He simply states his case and moves on.
I know that's how you would like to be, it's the ideal that you would want to be true to. But it's all rational thoughts.... Your feelings won't fall in line with these rational thoughts, trust me.
When the breakup is final, you'll have to go through the aftermath and it won't be pretty. It'll hurt and throw you off balance, actually it will KNOCK YOU DOWN, hard....
In those times, when you'll be in pain, you'll wish you didn't say all those nice things during the breakup. You'll probably hate yourself for it!
Do what you must, but I'll hate to tell you "I told you so...."
I'm not saying you need to be rude to her, by the way! Just be apathetic, no emotions, just business-like. I'd simply send her a text: "I'm breaking up with you, I'm sure you'll understand. Thanks for the good times, see you around"
She'll probably blow up your phone with calls and texts after that text. DON'T RESPOND! She's just gonna draw you into her drama, she'll try to make you emotional (read: weak and easier to be manipulated), she'll try to get the upper hand, she'll try to convince you to not give up on her blahblah. Then when you give into her and go into the process of giving her another chance, she'll eventyually dump you or cheat on you behind your back. That way, she'll be the 'winner'and it'll be easier for her to leave you behind. So don't fall for all of that, stay strong.
Sending her the breakup text and NOT RESPONDING to her emotional storm after it, will make you the 'winner' and it will make it easier for you to leave her behind.
Don't kid yourself, every breakup has a winner and a loser, there's no way around it. The one who gets dumped will feel considerably more hurt and will have a much harder time moving on. Make sure you won't be be that person. Yeah I know, you'll say that's no problem coz you are gonna breakup with her, not the other way around. But mark my words, once you've broken up, it'll be very hard not to give in to her when she tries to draw you back in. And while you engage in that process, you'll feel so happy that this 'might work out after all', only to get knocked down harder when eventually things fall apart and that time SHE will be dumping YOU. So she wins after all... And when that happens, you'll hate yourself for not sticking to silence in the past.
Women are fvcking whirpools. You'll swim at the outside of that whirpool, where its force is weak, but it's just the start of getting pulled in closer and closer to its center, very slowly, with each circle you make inside of its influence.
When you respond to her when she blows up your phone after the breakup, it's like swimming to the outside of the whirpool. Don't be stupid....
P.S. Fvck this bytch. I'm sorry for telling you about that possibility that you hurt her and she now wants you to make up for it blahblah. This is not the case, she's just being a cvnt, it's obvious. Women and their bullshyt... By now there are only two possible things to make from her behavior:
1. She's cheating on you
2. She's being a manipulative, untrustworthy, conniving piece of trash!
In both cases, she deserves what I suggested. Break up with her and be totally silent afterwards. She thinks you are weak and that she has you in her grasp, since you tried to get in contact with her today. So she won't know what hit her, and the silence will frustrate her very much. AND SHE DESERVES THAT! Fvck that moral highground stuff, that's just you responding to all the nice things she has shown to you in the past. Now she's showing you her dark side, which is disgusting, unfair to you, making you feel helpless for a month now. And that's what you have to respond to now! So don't be a moron, turning the other cheek when someone hits you on the one side... In the end, a breakup is a battlefield, don't kid yourself. One wins, the other loses. Which do you want to be?