I don’t know how to cope with this grief

My cat passed away this morning. She was 15 years old, and I’ve had her since I was 3. She’s been a part of my life from the very beginning. I honestly don’t know how to live without her.
I don’t know how I’m supposed to come home and not see her waiting to greet me anymore. I don’t know how to walk into the kitchen without her following me, hoping to convince me to give her a second meal. I don’t know how to take a bath without her jumping onto the edge of the tub, waiting for me to splash a little water on her face.
I just don’t know how to do any of this without her.
I really need help because I already miss her so much. We decided to have her cremated and keep her ashes. We’ll get them back in about two weeks to a month.
The house feels so empty without her. Seeing her bed sitting there, empty, breaks my heart. It hurts more than I can put into words.
My baby. My sweet little kitten. She’s gone.