((((((((freewill))))))) so sorry about your dog. we feel and grieve for them just like children sometimes. it's not easy to take an animal you love so much on that trip. i've been there and it is very painful i know. just try to find peace in knowing that you are doing the humane thing and the best thing.
you also said that we are here to do Gods work and your work is done. you can always do God's work here by loving and helping others who need you so much. and like others have said before me, your son will always need you. i am grown and i still need my mother to turn to for guidance and understanding. i hope this dark cloud lifts for you soon and the sun shines warmly upon your face.

best to you
recluse1