My husband can no longer be left alone. What people may be able to suggest with regard to my being away?

Rafaela, find a licensed Caregiving Agency and have them come to the house so you an interview them and they interview you.   But first tell them you are looking for someone to take care of hubby with only a couple of days notice on an as needed basis.

Some Caregiving Agencies have caregivers who only work "emergencies" when there is a last minute call.   Now, you may have to pay a higher hourly rate if you can't give them a week's or few days notice.   But after time the Agency may start giving you the regular rate.

And as time passes and hubby needs more care, and if it is in the budget, you can have someone come for 3 hours per day during the week to give you a break.

I hired an Agency for my Dad and we went through a few caregivers from the Agency before finding two that were a perfect match, two who could talk to Dad with common interests, and who Dad couldn't wait for them to come in for their shift :)

Having an Agency on speed dial makes life a bit easier.

That's how new I am to this part. Are there agencies that will come simply on an as needed basis?

Find an agency that you can use regularly when needed. It is too hard to be able to depend on unpaid, volunteers that look in on him, then what if they find a problem? Maybe they do not want to risk being stuck in case of a problem.