How do you deal with a person you know has Alzheimer's but refuses to go to the doctor to be checked out?

Go to a doctor and a therapist for yourself and share your fears and concerns. As you have probably read there is no cure for Alzheimer's but there are medications that might relieve some of the symptoms. Some are believed to delay the symptoms. There are charts to compare symptoms to. Also, you can pick up a kit at the drugstore to check for a UTI which can sometimes cause dementia type symptoms. He will need an antibiotic if he has an infection. You could possibly get that from an urgent care if you can get him to go to one.
Visit with an elder attorney to discuss your financial concerns and possible guardianship if your husband refuses to give you DPOA now. It must be vey frightening for him to realize that there is something wrong. I don't think you should pressure him about diagnosis but again, create a support team for yourself and let them guide you.
If you have been reading this website you've probably read that sometimes all you can do is wait for an event where you need to call 911 for him from a fall or injury or if he becomes violet or abusive. Be ready to ask for an evaluation at that time. You might keep a diary and record significant changes as they occur.
If he does have dementia it will progress and you will know for sure. Take care of yourself. He might refuse help but you don't have to. Hugs.

Thank you, I am definitely trying to take care of my self as everything from Home to Finances has shifted totally onto me.