I'm reaching a point where I don't think I can carry on as his caregiver, I feel helpless; is this normal?

Yes. Don't ignore the feeling of overwhelm. Get some help asap. Can you tell us more details of your situation?

Yes. It sounds as though you are being told by yourself that this is no longer sustainable.

Totally normal. We are humans and we have to care for ourselves first. Caregiving is so very hard. Please take care of yourself.

Yes it is and it's why so many people place their loved ones in care homes.