My best friend is moving and I'm already crying as if she died 😢

I lost my 10 year old dog to cancer that I was extremely attached to.

Not long after, I lost my grandpa to cancer.

Between these two losses a new girl started where I work. She was on the same shift as me and we had the same days off. Before I knew it, she became my best friend. I've never had a best friend this close as an adult. We are both single so we spent alot of time together. I saw her almost every single day for 2 years straight. Either at work, or hanging out at home, or both. We watched TV shows and movies together, grocery shopped together, complained about work together, went on weekend trips, told each other everything, I mean like real deal fairy tale type best friends. Something I never expected to find in my 30s. We both wanted to take travel contracts for our job and bounce around different places together. I was so excited and happy to have a best friend. I've had many friends in my life but never any I cared about the way I do her. I love her. I would do anything for her. Our plan was to do our first travel contract in January of this year but I am unable to go until next year. 4 days ago she told me she accepted a travel job on the other side of the country and she's leaving in in a few weeks. I have done nothing but sleep and cry the past 4 days. I can barely stop crying even when she comes over. I feel like my heart has been ripped out of my chest like when my dog died. Why is this so dam painful? I knew she was looking into leaving relatively soon but I had no idea it would wreck me the way it has. She tells me we will still talk and whatever but I feel so distraught over it. I know our friendship won't be the same long distance. None are. And everything here around me will remind me of her. She's going to a new exciting place so she won't feel the sadness and have all the reminders of our friendship like I do.

It will take everything in me to see her at work and hang out with her the next couple of weeks without crying. I hate feeling this vulnerable. She's so excited and I'm depressed. How am I supposed to be supportive and happy for her like she deserves? I feel so alone.

I've already been grieving other aspects of my life and this news just pushed me into a dark hole of depression. I don't know what to do.