Why do I push people away?
You push people away because closeness is asking your nervous system for something it has decided is unsafe, and distance is the fastest tool you have for getting the feeling of danger to stop. It is not that you do not want people near you. It is that some part of you learned, at some point, that being fully reachable is how you get hurt, and it has been running that program ever since without asking your permission.
What is actually happening
Somewhere underneath the argument you started for no reason, or the text you left on read for three days, or the plans you canceled right when things were going well, there is a threshold getting crossed. Closeness has a volume dial, and yours is set lower than you'd like it to be. When someone gets warm enough, consistent enough, or invested enough in you, a signal fires that has nothing to do with logic. It reads as irritation, or boredom, or a sudden urge to be anywhere else. You are not choosing to sabotage the relationship in that moment. You are discharging pressure the fastest way available, which is putting space between you and the source of the feeling.
Why it makes sense
This reaction did not appear out of nowhere. It got built by something, usually early, usually repeated: a parent whose attention came with conditions, a household where needing something loudly got you punished or ignored, a first serious relationship where opening up got used against you later. The nervous system does not forget those lessons just because you are older now and the people in front of you are different. It generalizes. Closeness once meant exposure, and exposure once meant getting hurt, so closeness still trips the alarm even when the person setting it off has never once been the danger. Pushing them away is not a character flaw. It is an old, once-accurate prediction firing in a new context where it no longer applies.
What actually helps
The instinct to distance yourself is faster than your thinking, so you cannot out-argue it in the moment it happens. What works instead is naming the mechanism before it runs, out loud if you can manage it: telling the person, plainly, that you tend to pull back right when things get good, and that it is not about them. This does two things. It gives them information they would otherwise have to guess at, usually wrongly, and it gives you a half-second of awareness the next time the pull-back urge shows up, which is often the only gap you need to choose differently. The goal is not to stop feeling the urge to withdraw. It is to stop obeying it automatically.
When this runs your life, it usually traces to one underlying pattern. For this, it is most often the Ghost rhythm, the thing under the behavior.