Vascular dementia and Alzheimer's : Support & tips welcome

My husband was diagnosed 4 years ago with both vascular dementia and alzheimer's. Though his mother passed away in 2009 with alzheimer's and my sister in 2023 with dementia he at times is in denial of his own diagnoses. He tells his friends and family that it's me making it up. He's not able to drive anymore at doctor's orders, and that didn't and still doesn't sit well with him. I do have a hard time with him when we get out. He makes gestures at other drivers or tries to tell me how to drive. Which frustrations us both. He's on medication now and has been but I know the worse is yet to come. My biggest fear is that he served in the army. That one day he may think he's back at war and think I'm an enemy because I'm Hispanic and he's not. I helped with his mother until her passing and with my sister until her passing and i experienced what changes they go through. It wasn't easy and so hard to see their changes. I don't have anyone that I can count on for help. Other than God, I have no idea how I'm going to handle things when he startes to change. June will be 5 years he was diagnosed and fear his medication won't be as helpful to slow down his progression. Any and all help with support groups or advice from those experiencing issues like this is greatly appreciated. Thank you very much for your time in reading my post.