My dog is 9 and I can’t sleep

So when I was 22 my parents and I got a dog (my first) and i fell in LOVE with him. Four years later I got married and my husband and I moved into an apt so I didn’t bring my dog because my parents had a house with a huge yard and he’s super attached to my mom and that was his home. My grandma also lived with them. Then my grandma passed away, my dad left and my mom moved into an apt. By this point my dog being 6 had lived with my mom his whole life and even though now my husband and I had a house and two other dogs I didn’t bring him to live with us. Him and my mom are super duper attached.

But…. I can’t help but feel so much guilt that he’s living in a small apt and is alone when my moms at work while I live in a house with two dogs. I feel like he may have been happier in a fuller house instead of just my mom but at this point he’s 9 and a change of home may be hard plus my mom says she can’t live without him. I may be crazy but I lose so much sleep at night thinking about how much of his life I’m missing were now 2 hours away and see my mom and my dog every two weeks maybe. It kills me that he’s 9 already and everyday I wake up I think about how many more years we may have with him and I’ve become obsessed with counting the days to his next birthday and being depressed that maybe I could’ve given him a better life 🥺

I will add that my mom takes very good care of him she lives alone so her entire attention is on him. Makes him organic food, spoils him all day and loves him more than anything.