There are 2 types of long hair:

The long hair we see on the internet

We have the ability to focus on the hair and individual(s) of our own choosing, thereby increasing arousal and decreasing overall sensitivity (over time). In other words, it becomes the norm, however unreal in real life.

The long hair we see in real life

I don't know about y'all, but what is long hair in real life is far shorter than on-line. But, it's the reality and being in proximity to the person that offers the stimulation.

So, adjust your expectations, take a break, short, long, whatever. The best thing to do is to occupy yourself with something else of interest. That will give you the time and space you need without worrying about "how long it's been since the last time I viewed long hair."

The doctor has left the building...