I know you must be so worried about your baby. I think he would definately let you know when it's time and I hope that he lives for a long long loooong time, I've not had an old dog recently, when I could remember things, when I was younger we had older dogs but I can't for the life of me remember, so I don't have advice for anything like that really but I think it sounds like he's just experiencing what, probably, all older dogs do.