What is the deal

Why am I so f****** unhappy
I love my job, have a great apartment.
Make good money, car is paid for.
Guess I’m starting to feel my age!
My g/f is half my age (30) but is borderline psycho.
I’m sitting in starbucks sipping coffee while she is out with friends at a kink party....I just wasn’t feeling it, so I passed.
I don’t think any of my friends or family know just how unhappy I am....
It’s brutal...