It's not always fun.
"sometimes I wish I didn't care so much about music" - Busdriver.
If you're scared of losing it, just means you love it.
but to say its always fun? nah, its hard a lot of the time.
I hate having deadlines.
I had to write two verses for a recording session the next day, a while back.
Finished at 8 am, fell asleep, woke up an hour later to go to the studio, that wasn't fun.
It's like a relationship. You may love your wife, but you still want to cuss her out every now and then.