My son and his dog

My 19 year old son that lives at my house ( I dont even live there right now ) has a dog that we have had for several years. His name is Rusty and he is part minature doberman pincher and part bat or deer I think. You would have to see him to understand. My mother gave me this dog many years back as my Uncle David thought she needed companionship and gave her this dog that he had rescued from abusive people. My mother in turn decided that my sons and I could use a new dog and she or her husband were not keen on having him. Anyways he is quite old but he is Dakotas best friend. He got pretty sick last year and in away I was hoping that the vet would want to put him down because I can see alot of pain in his little face. The vet said other then pulling Rustys teeth at $500 he just gave him some antibiotics and sent him home. He has done much better but still cannot walk on his back right leg.Dakota went out camping with some friends on Saturday night and when he got home Sunday he found Rusty very sick and not able to move very well from the back yard, where Dakota had him set up with a bed and food. Under further investigation, he noticed that between Rustys legs quite near his male parts were some kind of wounds that were bleeding and quite large so he called me. I called the vet yesterday and got him an appt for today at 2:10 and took a check to Dakota to pay for the vet and to check Rusty out. It made me cry. This poor little animal has what looks like to me to be abcesses (sp) that are bleeding and smell horrible from infection. His teeth are rotting out and he always has bad breath. But the thing is, is that my Dakota loves this dog to death. He is Dakotas best friend through thick or thin. He is going to be so heart broken if they have to put him down but I just dont know what to do. I cant put out alot of money for a dog that is in alot of pain and old but I dont want my son to be broken hearted. Its quite the dilema but I guess thats what happens when you have pets. I just dont want to hear the news today from my son. He is so precious to me and I hate to see him hurt.  I have also been really depressed lately and ofcourse there is not really a reason. I dont feel that Al loves me anymore and that I am just a pain in his ass. I have not been very loving in a sexual way as the meds make me to numb so I have to kinda fake that part of our relationship but lately have been just to tired to even do that. Al is a really good man, better then most and I dont want to lose him but I just dont know what to do anymore. It frustrates him that we are not being intimate and it frustrates me because I dont want to be. In the good old days I would just move home and drink myself into oblivion but that isnt the answer either. I am just so depressed for some reason and need to pull my head out of my ass. I have had plenty of unsucessful relationships and I dont want to lose Al but it seems like I always screw up some how. Oh well I will get through this and pull myself out of it.. Just really stressed and tired.Oh yea, still sober... This is my story and Im sticking with it.. Peace.. Y'Vonne