Well I normally dislike very very long hair. Sometimes it looks nice sometimes it doesn't.
When 'you' say that you would never cut your hair, does that mean that you don't get trims either to keep it healthy? Most of the time that is why I don't like it, it needs a good trim.
I have worn long hair (in HS I had it permed and it was down to almost my shoulder blades -- in the days of BIG HAIR!!!)
and now I have short hair. I feel better with my short hair (way above my shoulders ) It gives me more self confidence and that is what I need as I have pretty low self esteem anyway.
PCB if you aren't sure about using the henna b/c it might change your hair color. I wouldn't use it. Personally I love to color my hair but that is b/c I wasn't happy with my hair color. But you seem to be very happy with yours so keep it!!