Sometimes we need to stand back and look at the problem again.First you said he was seen by your vet.Did he do a urine test for diabetes,I have seen a few dogs in our town who has this problem.If you have not done this talk to your vet.
As for the problem this is causing you. It seems you both need to talk with your vet,on a 1 to 1.Maybe he can give you some information on the problem and what way to go with this.I sure hope you and your family can work this out,as all of you love Parker and he is a family member,I hope and pray all of you can sit down and work this out,putting down a time line is not the fair way to go,if everyone did this with there animals or there kids this world would
go down the drain.....................my prayers are with all of you..cathy