Where can I find help caring for my wife with dementia?

Try calling the Alzheimer's organization in your community or go to www.alz.org. Your wife's dementia may not be Alzheimer's - you didn't say. It could be vascular or another type, or mix of dementias. But all the same, you will get good advice and support from them. Also, please check the topics on agingcare.com for support from other caregivers.
Take care of yourself, too.
Carol