You can contact Social Services yourself - you dont have to go through your GP.
Contact them and ask for a needs assessment for your husband and a separate carers assessment for you. I am not sure if you can access the continence clinic yourself, or whether you need a referral from the GP.
Is your GP aware of all the problems that you are seeing or does he only know what your husband is telling him and not your side of the story? It is usual for people with dementia to not have any understanding of their problems and needs and say that they are fine. If this is the case, please make sure you tell the GP what is actually happening - write him a letter if you are unable to see him on your own. I know this feels like betrayal, but it is not - the doctors really, really need to know what is going on, for your husbands sake as well as yours. The symptoms you describe sound more advanced than early stages.
PS, problems with chewing and swallowing are common as dementia progresses. Tell the doctor about this too and he can refer you to the SALT (speech and language therepist) team, who are the experts in this sort of thing. In the meantime - go for soft things like shepherds pie, mashed potato etc that doesnt need chewing