Hugs and sympathy Jeza. You are doing a fine job, but maybe you can make life a bit easier for yourself. With our aged ones (v. old. frail, dementia, living 'independently') we've managed to find a wonderful group of carers who have formed their own business, and one of the three of them will be in every morning to bathe, chat and generally check how things are going. There could be something similar near you, and if you can get it, it will ease your workload. You should be eligible for a grant to support this from your social services. It's all a pain to set up but you won't regret it as you both go forward.
In addition, you can get disposable pull-on incontinence pants, so you aren't burdened with laundering accidents. Apols if this is something you already do. We've found it has made a big improvement in the management of our incontinent rellie. Meanwhile look after yourself as you are under considerable stress.