Can my husband be my Certificate Provider?

No. A Certificate Provider cannot be a family member of yours or of any of the attorneys you've named. The law requires the CP to be independent — the whole point of the role is to confirm you're acting freely and without family pressure. Your CP also can't be your business partner, an employee of you or your attorneys, or an owner/employee of a care home you live in. The options are someone who's known you personally for at least 2 years (a friend, neighbour, work colleague) who isn't named in the LPA, or a qualified professional (doctor, solicitor, or someone like us with the right professional skills).