PN, I'm worried about you. I see the similar signs of my mental anguish caring for Don. I think CLKD asked an important question about what help might be available to you. I knew no one and could not leave my new home so I just somehow got through it, but I hope maybe you have someone to call to visit with your husband if necessary so you ca get to an appt. for yourself.
I hate to hear your feeling of guilt taking the sleeping pill. Your doctor should have been more specific, but those on this great forum, who have taken it, may be more helpful if your doc can't be more specific for your needs. I use Valium because instead of a two hour half life, it has up to a 200 hour half life so I don't go up and down as much - MY guess only here.
None of us can prescribe, but I think a mental health person might be more helpful in finding what temporary medication would best suit you.
Your strain is in some ways worse than mine in that mine had a time limit. Mine was worse in that there was no hope. You must protect yourself more than you are. We can only last so long. Please get some support of a professional type. I think the NHS does so much better than US on this.
My heart is with you.