I had a similar situation with my first Cocker, Josh, so I understand why it's getting you down Robbie
Josh started to go deaf when he was about 9 or 10, then started to lose his sight when about 12. Eventually he was blind and deaf but, like Charley, coped pretty well. He still enjoyed his food, cuddles, saying hello to other dogs and going for short walks in the New Forest.
Later he became mildly bladder incontinent when sleeping, but was fine when awake. He also started to get a bit senile, taking a while to realise where he was when waking up. Once awake he was usually OK but had a few distressing times where he'd wander in circles or just stand still, wagging his tail forlornly. He was prescribed Vivitonin
http://www.buyvivitonin.co.uk/ and that helped.
I don't know what to suggest about the incontinence, but perhaps Vivitonin could help to perk Charley up generally. I really feel for you Robbie, it's so sad seeing old age catching up with them