18 1/2 years and died in my arms.... know exactly where you're coming from...
I still reflect and mourn all my furry companions, and some feathered ones too... 4 German Shepherds, 1 toy Poodle, 3 cats, a beloved cockatiel and an assortment of canaries and terrapins...
I was never going to have another after this last cat, but eventually decided to foster to get an animal out of a kill pound to prepare for a new home but he has since adopted me.... I'm a proud 'foster failure'...
I hope you one day look for another pal at some stage... maybe a rescue.... 'out of cages onto couches' is my motto...
sympathies to you.... nothing really helps ease the pain of losing such a close mate, but it softens a little over time...