Spouse has very early dementia?

Hi I am fairly new here. I believe my husband has something going on cognitively but I am so confused. We cared for his mother when she had Alzheimer’s off and on for about 8 years but don’t know if that is what is happening with my husband. Very different than with his mom. But I feel like I don’t know this man I’m married too. He will not go to our doctors. I’ve talked to our doctor and he has tried various ways to get him to make an appointment. He can go to the VA also. He did start to go and his doctor sent him for therapy ( Depression) but he does not tell the therapist everything. He will not let me go with him. I’m sure he does have some depression but there is something else going on. He won’t do anything anymore. He doesn’t take care of our yard etc… only mowed 1x this year. He loves fishing and has always fished and hunted . He literally sits and watches tv day after day. His hygiene isn’t as good. He never wants me to leave the house. When I do he tells me I’m always gone. His newest passion is grocery shopping. He looks at the ads as soon as the post online Wednesday morning ( 12:00am) . I am 63 and he is 66. We have been married 44 years. His personality is different . He talks stupid things like he’s a teenage boy? Gives me nicknames that I hate and calls me that all the time till he thinks of a new one. Right now I’m Scraper. He will ask me if we are ok a lot. If I’m in a different room he’s constantly asking what I’m doing. We no longer sleep together because about 2 years ago he started telling me he couldn’t sleep with me I kept him awake? We have a non existent sex life, once in awhile he calls something a odd name. I’ve talked to him several times about these things he has a reason for everything. We bought supplies to redo our trim 3 yrs ago (it needs replaced) it still sits in our garage, wire fencing for our yard also and lattice for around our deck. He has called Turkeys Robins, a cookie sheet a scraper, a coaster for a drink a puck etc… he sleeps 8-9 hours a night but always lays down later and takes a nap. His penmanship has changed and is really squiggly. I’m just in a place of limbo because he’s very different, personality etc… everyone ( our kids , grown grandchildren , friends) have noticed he’s different. I guess I m wanting a Doctor to confirm there’s something because I feel guilty thinking it. But I know in my heart it’s something. What ? Not sure. We have always had a good marriage, good sex , spending time together , doing things etc… Right now I feel like a roommate. I’m so sad yet scared at the same time. This has been for over 2 years.