My husband has dementia. He's angry, yells and criticizes me and my 16 yr old constantly. He's also delusional and hates everything. Advice?

You mention in your profile that he has Alzheimer's/dementia. Has he been diagnosed with Alzheimer's or another form of dementia? The reason I ask is there are some forms of dementia where violence is more apt to be a problem.
Discuss with his doctor about medication for anxiety.
And is the doctor aware of the delusions?
Once he is properly medicated and even properly diagnosed hopefully the anger and delusions will be less of a problem
BUT if they continue you need to protect your son and yourself as well as your husband. If at anytime you feel that you are in danger you must call 911. Tell your son the same thing if he happens to be home and you are not.
When you call tell the dispatcher that the person is threatening you, your son or himself. Tell them that your husband has dementia. (I think the response will be different than if they think they are going to a different situation)
It might be time to think about the What If's. If it is not safe for him to be at home you will have to think about placing him in Memory Care.

If medications haven't yet been prescribed for his behavior, I would start there. If they have and just don't help, then it's probably best that you think about getting him placed in the appropriate facility. You nor your son, deserve to have to put up with his bad behavior. Wishing you the best.

For the sake of your son and yourself you made need a legal separation and a report of adult at risk if there is no way to handle this Debra. I am so sorry. Is your husband diagnosed? Are you his POA? Have you considered placement for your husband? Not knowing more details makes it impossible to offer any advice. I am so sorry for these dire circumstances for you.