Hello, dollydee.
Yes, the anxiety is definitely familiar, I'm sorry to say, and I'm sorry to hear you are having trouble with it.
I absolutely know about that anxious feeling first thing in the morning (and also last thing at night, preventing sleep), and the headaches, and the aches and pains, all of that.
I would say these are the things that helped me:
-more support for me (TP, support group in real life, having more help around the house or just me doing less, and my mother moving into a care home)
-seeing my doctors, one of whom is wonderfully supportive
-a stress reduction class that taught some relaxation and meditation techniques that have helped a great deal
-off and on, a therapist (counselor) to talk to
-a massage therapist (whom I see more than the other therapist! The massage therapist got rid of my headaches, which were caused mostly my stress and muscle tension, and keeps them and a lot of other aches and pains at bay, or under control)
-better diet
-exercise
-getting outside whenever possible
-making sure I have time for at least a few things that are important to me every week, like a favorite exercise class, or social time with a friend, et cetera
I understand that caring for a spouse is different to a parent; my mother, who had been living alone with only me to support her from 100 miles away, finally had a minor crisis, went into hospital, was sectioned, and then deemed needed to have a secure care home placement.
You sound like you have a LOT going on.
Perhaps you feel overwhelmed by all the admin and laundry and bits and pieces because when you add those to your work and then add dementia to the mix, it is overwhelming.
I would strongly suggest you delegate or hire out anything you can, such as laundry, cleaning, gardening, jobs around the house, et cetera. Even doing some of the shopping online can be a relief (two years after my mother went into the care home, I still do a lot of shopping online--I often can't face the errands).
As far as your husband goes, I would seek support for both of you. This could be carers coming in, day care, respite, carer's cafes and support groups, singing for the brain, paid help, whatever will be useful to you. Nobody can be the lone 24/7 carer for someone with dementia, forever, with no help or support, without risking their health and/or carer's breakdown. (The statistics about carers who get ill, break down, and/or die before the person for whom they care does, are grim.)
If you were caring for your husband with dementia and a colostomy bag, without anything else on your list, I would say that you would already have a very full plate.
The sad thing about dementia is that it is a progressive disease, things change (sometimes constantly), and eventually, it gets worse. I have learned a few things about dementia, and one of them is that it will absorb as much time and energy as you throw at it. Another is that you should never refuse any offer of help, even if you don't think you want or need it.
I will let the UK residents talk to you about your Local Authority and Social Services and so forth, but if you are not already in the system, that's a place to start.
I hope you will find some good advice and ideas here on TP, and that you can find a way to get more support, and reduce your stress and anxiety and be able to feel better. Very best wishes to you.