Can someone give me an idea what the hell is wrong with my husband??

could be... but might not be. confusion along with forgetfulness is more of clue to that, but i'd consult a doc, because there are many types of dementia, some of them due to a simple nutritional deficiency. note whether or not he's clearer in the morning versus the evenings. see that he's staying hydrated, because that can exacerbate dementia, and forgetful people often forget to drink enough water. maybe make a daily journal tracking his memory performance.

When was the last time he visited your family doctor? Perhaps routine bloodwork is in order. And some questions to test his memory, short-term and long-term both. It could be any manner of things. Is he depressed? Stressed? Just slowly forgetting? Maybe these topics are not as important to him as to you? Please follow my advice. Don't be overly-concerned. And check it out.

If there’s behaviour change he should be checked medically

He is maybe a man? Or dementia?

Worth reading with lots of ideas about what could be behind the issue:
https://www.webmd.com/brain/sudden-memory-loss

Lime Disease
Anxiety
High blood pressure
Pain
Depression
Vitamin B12 Deficiency

and more listed in their slide show on sudden loss of memory or brain fog.

My wife is nearing 70 and has been diagnosed with small vessel disease in the brain. She exhibits much of the same symptoms in particular with short term memory issues. Also keeping things in perspective like timelines. And yes, it does lead to dementia.

Give him a lot of chances. I believe time isn't too long 🙏

Definitely sounds like the onset of dementia. Or he has had a minor stroke

Yeah, this sounds like a memory issue. Time to see a doctor.

He could be just stuck in his ways and reluctant to change

Has he always been like that

If this is not normal then, yes, I would at least be aware and take note of things.

If this is something he has always done then it is something else.

My husband is likely undiagnosed for ADHD. We have whole conversations over and over.

It's called alzheimers