It's not ridiculous. Losing a beloved companion -- regardless of species -- hurts to our very core. Someone who was part of our daily life is gone, a relationship of years is over, and no one else can totally understand the grief.
It sounds trite, I know, but healing takes time. At first, the grief is overwhelming, and it will come and go in waves, just like when we lose a human companion. But one day, it will hurt just a little less. And, a little less after that.
That doesn't mean you didn't love or won't still miss your girl. She was incredible, and you were lucky to share so many years with her.
The worst thing about having animal companions is having to outlive them, to make sure they are loved until their very last moment, like your sweet silkie.