I will add here that I think we should always examine ourselves to see if we are legitimately to blame, or bear some responsibility in the erosion of a relationship. If we do bear responsibility, then we should step up, take the reigns, and correct it.
If your girlfriend has some legitimate gripes with unreasonable behavior on your part, she is then legitimately confused and you should endeavor to find out her perspective.
In such a clear case, the man needs to step up, and take control and responsibility. He should sit her down and talk about the relationship and define expectations on both sides, while being ready and able to take the leadership role, which is what women crave, and rightly so. But all too often, the man waits until she has already checked out. If that is the case, then he needs to eject. In this case, the fact that she goes MIA and does not answer some texts is a huge red flag showing that she has already checked out.
I maintain that since things have degenerated to this level, where you, OP, even think that you're about to be dumped, the best thing to do is to flip the script, resulting in her suddenly having to deal with rejection, all of which will bring out the truth.
My whole point with this particular post, men, is that we as men need to take responsibility for our relationships and treat the woman as we would like to be treated. A woman who truly feels neglected, as long as she's behaving like a decent woman, has every right to become confused and consider ejecting.
YOU are responsible for your relationships. Not her. If she responds to your leadership the way a woman should, then great. You will perceive compatibility and an easy relationship. If you are in and out, there and gone, or otherwise showing one foot in and one foot out, you will reap her confusion and will eventually be dumped.
One thing the community never seems to teach is the man's responsibility for his relationships.