We have to prepare you for your confrontation speech.
As you keep heading in the direction you are now in, she will be getting more curious to what is going on in your mind. (she has already hinted that she is now wondering what in the world is going on and hoping she isn't losing control of you)
At some point.. (not now, too early) she will ask you what is up with you and why you are acting this way..(she has already hinted a couple of times in only one day of this change in you)
You need to start practicing your response....
It will start with..... "Well, I have been doing some thinking. I HAVE DECIDED that" (and then you will fill in the things YOU have now decided) such as.. I don't want to be with someone who just ups and leaves... I don't want to be with a woman who can't make up their mind... I don't want to be with a woman who is texting another man.... I am going to be with someone who.....(fill in the blank) I realize that you are right and I think it is a good idea that we spend some time apart. I need some space to think..... Those are the types of thoughts and things that you will say when you give her your.. "I HAVE BEEN DOING SOME THINKING AND I HAVE DECIDED speech...
Not now.. Too early.. It won't be long though, so get your "I have decided comments ready in your mind.