My heart aches for you.
How do you move on? After my beloved dobie passed on years ago, I went to the local SPCA to drop off her beds and toys for the shelter to use, and a nice volunteer understood why I was sobbing and gently offered to let me sit in a socialization room with a sweet puppy--not to adopt, but just to be. That little dog licked the salty tears and snuggled against me and fell asleep, and it was the first moment of peace I'd felt in days--at that moment, I knew there would be another dog in my life, not this puppy, but some other dog would inhabit that space in my heart. The loneliness wouldn't be forever.
More recently, I moved on by foster-failing. The shy little pup I'd brought home to foster ended up rescuing me when our old female died unexpectedly of hemangiosarcoma in April. That pup's presence, love, and sweetness got me through that dark, grief-stricken time -- and after that, there was no way I wasn't keeping her. She came to us for a reason, only I didn't know it when I brought her home to foster her.
My strongest advice right now is to find yourself some puppy therapy--if not at a shelter, somewhere. The smell of puppy breath and the softness of their little tongues is the best balm for an aching heart. Even if you won't be ready for another one for a while, just holding one for a little while will make you feel better. It's amazing how much it helps.
I'm so sorry for your loss.