No, that is not a symptom of anything, but it might mean something specific to you, and have some real psychological importance, so its worth trying to figure out why this is the only way.
so if your hair isnt in a ponytail what happens? like when u shower or brush it? how about a haircut that makes a ponytail impossible?
I think cutting your hair now would be a bit dramatic and could potentially be quite stressful.
I generally wear my hair up too and feel rather insecure if it is down or loose. It can be a personal preference or a practically.
I think wearing it up (all the time) can highlight a need for control. I don't really like things that are random (unpredictable) or chaotic.
Wearing my hair down can also leave me feeling insecure. It is different and new and can be quite stressful.
You could always try leaving your hair down for a little while and see what thoughts and feelings you have.