Yes, PIP cannot be claimed for the first time after pension age. Attendance Allowance is the one to claim, though PIP can continue for those already on it. It is worth noting that AA does not have a Mobility element, so anyone approaching pension age should claim PIP before it is too late.
62Granny, your husband must be already getting a disability benefit, probably PIP, for you to be getting Carers Allowance. At least 35 hours care a week is needed to qualify.
Turn2us, and entitledto.com, are online sites you could look at and put your details in to see if you are entitled to any other help. Even if you can’t get Pension Credit, you may qualify for Council Tax reduction, which is administered by your local authority, not DWP.
There are also grants available. It is worth putting in your former employment, or your husband’s and you will be surprised what can be claimed for various jobs and professions.
Age UK and Citizens Advice are both good on benefits, on their websites, or by phone, if you can’t get a face to face appointment.