I am sobbing for you. I have been where you are.
I was in your shoes 12 years ago. My month-old son died. I begged him to come back. I screamed at the sky and I have never been in so much pain in my life. It physically hurt. My arms ached. Everything hurt. I did not want to live.
I could bullshit you but you do not need that. I am going to be honest with you. There is nothing that is going to make you feel better right now. It's not supposed to feel better. You are now in a club that nobody wants to be in. But we are here... you are not alone in this... and the people who know what you now know and see what you now see about the world can sometimes save your life because your life is now being lived in a new language. So I am going to start with what saved mine. These were passed to me and I have passed them and some day you may see fit to pass them as well.
Right now - grab his dirty clothes. As much as you can, you seal them in something airtight. Inhaling the smell of your boy is going to get you through the worst days.
In the coming days - You are going to see people with their children. You are going to feel like they have come into your presence to personally remind you of what you've lost. You should have a heads up - it is going to hurt. You are going to feel a physical compulsion like you've never felt before to lash out at these other parents. If you act on it, you will have another thing to grieve later - find a way that you can lash out without harming someone. Punching bag, gardening, machete to a tree, screaming in the woods... whatever it is that lets you release that energy because it's going to feel like you need to physically lash out. Just know it's coming and have a plan.
Probably the most important thing I was told... Before he is laid to rest, hold him. Feel his weight in your arms. Remember it. Hold him, and hold on to that moment. Run your fingers through his hair. Trace his eyelashes and the ridge of his ear. Hold his hand. Not a single one of us who has acted on this advice has ever regretted it. You will not regret it and your wife will not either.
It is okay to not feel up to seeing people. It is okay to prioritize your grief. It is okay not to rejoin the world when it starts moving again. Stay there for as long as you need to.
It does not feel like it right now, and it won't for awhile - and when it starts to you'll want to reject it with every fiber of your being - but it does get "better". That's the closest word, but it doesn't really get better - I don't know that there is an actual word for what it is. The days become less exhausting. You will smile for the first time without feeling the need to pay a penance. You will start to feel the tangibility of being able to live again. It will never be the same, you know this already; and "okay" and "peace" do not mean what they used to but both of those will come. You'll be able to carry the bricks on your chest and the ache in your arms with less agony. You'll find that they, and other ways that will be personal to you, are the way you can love him actively.
This is going to hurt forever. It will not be this acute forever. There will be days years from now that you will feel the same as you do today but its weight will be more bearable when they come. It never stops hurting, but it will not hurt like this forever.
Speak with others who have walked the path you've been thrown down onto. They have heard, felt, thought every single thing you are thinking right now. The things that make you wonder if you can ever say them out loud - they are normal. We have all experienced these. It's going to make you wonder if you're crazy and you're not. You are as deep as a human being can be right now. This is all normal for where you are.
Compassionate friends has chapters all over the place - this is a good place to find your tribe. I am available to you and your wife as well if you'd be comfortable with that.
Regarding your marriage... Recognize that you both have an individual path to walk and you each will need to honor that. It will help you both if you find a way to draw connections, but understand that your grief does not look like hers and hers does not look like yours. There is only one person in the world who will know what it feels like to lay your baby to rest. Sometimes you will want so desperately to feel understood that you will want to either bring her to where you are in your grief or go to where she is - it is possible both to tend to her and tend to yourself. Do not neglect your grief trying to tend hers. This is a very common thing for men in particular to do. My husband did this, and it complicated his grief immensely. We made it through but barely. There are places where your grief and hers will intersect, but you each have your own path.
I mourn with you. I truly do. I wish I could take this from you- if it were possible for us to carry the worst for a newly mourning parent simply because we'd been there before I would. What I can do is to offer my support and an ear if you or your wife need to cry or scream, or verbalize the things you're thinking and feeling that make you wonder if you're crazy. I am so sorry that you are in this club. We all wish we weren't. The cost is high but the people who speak the same