"You'll get frown lines from being so serious"

I am tired of hearing that I'm "too serious" and to "let loose a little and go with the flow". That "you're young, have fun" or "it's not that deep". Unfortunately, I do not have the privilege of being able to do those things. I struggled so badly when I was young, that I had to learn new habits, enforce new schedules, create rules and routines for myself. I created the stability and structure that I lacked in my life and learned to be organised and in control in order to avoid the anxiety and pain of surprises. So yes, I am disciplined and harsh on myself, but I need to be. I cannot afford to let my guard down because that is how I lose control and end up hurt. So I will stay serious and reserved, because it protects me. And asking me to let go of that will kill me.