Napoleon's eye removal surgery

Napoleon is my 8 year old Boston Terrier. Until August of this year he has been in perfect health.  In August he developed a "melting ulcer" that covered 80% of his eye. We took him to the opthamalogist at Summit Vet in Tacoma.  He was treated and everything seemed like it was going great...until today. He wouldn't come to work with me (which is our normal routine) so I left him home.  This afternoon as my husband was sitting there, "Poly" started whining really bad (which he never does) so my husband got up to check on him and see what was going on. He was bleeding from his eye, and the specialist said if it does that then he has to get to the vet ASAP. We talked it over with the vet and felt removing the eye is the best course of action. He has an underlying disease called Cornial Endothelial Dystrophy and we know he's going blind. But with the ulcers it makes this excruciatingly painful for my poor baby.  I know everyone says their dog is the best, but seriously Poly IS the best. He's my shadow, my companion, my cuddle buddy. Never judging unless I won't let him sit on my lap. I am lost without him. His surgery is scheduled for tomorrow at Wheaton Way Vet Hospital. Its suppose to be his vet's day off but he's coming in specifically to do the surgery. We have been quoted $1700 to $1900 dollars for the surgery. At this time we only have $500 that we can put towards it. Any help would be greatly appreciated.