Hey Wayne, long term ADT can certainly predispose one to depression and negative thoughts, so anti - depressants might help.
But add the loss of a beloved pet to the mix and that’s the absolute worst! I lost the Maine Coon love of my life almost 3 yrs ago and I still tear up at his memory.
He was a true living gift who made my life so much better with his presence; when we lost him I cried ( I mean the full blown ugly stuff with snot and hiccups) for months, couldn’t sleep…it was horrible.
The only way out of the funk was to get another kitten; not a replacement for the irreplaceable, but another vital spark of life which needed to be cared for, nurtured and loved.
It’s not a betrayal of your devotion to your beloved departed pet if you get another; many people seem to feel this way but I’ve come to learn that if you gave your pet the best life he/she could have had, then no regrets are necessary.
It might be time for you to bestow your love on another animal who is out there looking for a place to call home…Best
Phil😽