What should I do?

[Queen_of_Swords]

Well a huge problem is the 8 year old in your bed.
I too have the same issue. My little one wakes in the middle of the night goes to the toilet and wanders to my( once ours) bed.

Part of the reason is that he kicks off the covers at night and gets cold so he's seeking warmth and comfort. That was solved with making up a couple of cloth bags with rice and heating them in the microwave to put to bed with him. They release heat slowly over the night.
If he's missing you or Mom, either of you can wear a shirt for a week and put it in bed with him so your scent is there if you are not.

The other is ease of access. If I lock the door, he can't come in and goes back in his own bed, or joins his big brother.
It is a developmental issue too. As one poster pointed out, it tends to stop when they hit 10 years old.

From your wife's perspective seeing as your son is hitting her up in the night, it's easy to let a kid in bed when you're sleep deprived, tired and just don't have the energy to fight them and kick them out of your room. A little planning and talking goes a long way to your spouse and to the child

"Son I know you love to crawl into bed with us is really nice and we love cuddles" ,then state when it's permissible and when it's not, and what the consequence will be ( discuss this with your wife before hand so you're on the same page). " Honey I know you're really tired when X comes to the room so, let's agree to do this ______when son wanders in. I love you and want to be with you spending time in peace and with privacy.

If you don't have a lock on your bedroom door, get one.
Perhaps consider that it's you that has to escort the child back to his own bed when he does come in. You may have to take control here to get what you want.
None of this is easy Forest, but you have the opportunity to take the lead. I know you're tired and feel like you've done nothing but give for very little return.
But it goes back to what Denver has posted a few times already.

What's your defniniton of unconditional love? What does it look it like? Is love a feeling? Is it a decision and choice? Is it a noun or a verb?

Forest you're not alone here, if you look at some of my posts you'll see the same longing in them.