Oh I am sorry, it is heartbreaking ....
Time is whatever you need, it doesn't matter what anyone else thinks.
When I lost my faithful old lad Jethro, I was devastated, but even more devastated than I was Maisie our other dog, who had been with him since she was a puppy - she pined and pined for him crying all the time, it was awful to see - and so I got her a new rescue companion within a week - and she returned to 'normal' quite quickly. That wasn't my initial plan, but it had to be done for her, and "Dora The Explorer is a lovely girl, albeit a bird murderer if she gets the chance!
Do what you need to - they NEVER replace the one you have lost, but they occupy another bit of your heart and become family once again ... x