Littlek
Littlek, I absolutely understand what you are going through. Having gone through this heartbreak several times with my cats and dogs, I've learned that loving your animal means not prolonging their suffering when nothing can be done to cure them. I've also learned that not acting when appropriate is to ease the agony of loss by the human, not the best interests of the animal.
True love is to be able to let go when suffering is involved. Very hard to do, but the most humane kind of love. If only we treated humans with as much love.
Littlek, I know you are the kind of loving person who thinks of the animal first, not yourself. After your dog's suffering ends, you will feel better for having done the right thing even while you weep for your beloved dog.
BBB