Parenthood: trying to get the 'single/shared' part of it right . .

Blogs can be funny things. You can write what you want; when you want and how you want.
But sometimes an idea resonates with you to such an extent that you are actually fearful to write it, but really, the best thing to do is get it off your chest and hope that whoever reads it. 'gets' it and may even know or be someone in a similar situation.
This isn't about work or a great friend or a new shoe or a social event or a travel destination. It's about motherhood. Single and shared motherhood.
And with me, one of the hardest and most emotional parts of it is having to hug, kiss and say goodbye to your child when the time has come for him (or her) to go to his dad's house. And I am sure, it's vica-versa in many cases.
Thankfully our son has a dad who is a brilliant, 100% father who adores him as much as I do. But the guilt still sticks and sticks and sticks.
Sure, there are moments of freedom (like you used to have, post-baby) when your time is your own. You do get to have those nights at home on your own. See friends you may not often see. Book in meetings or work at odd hours as you won't have a 'sitter' to pay. You may not have to make the breakfast or the school lunches for a few days, or make sure the uniform is sorted and the after-school activities are set for the next day. But there are times when you just feel out of the '24/7' loop of your child.
Important school notes get stuffed into his schoolbag that I may not see (and vica-versa) so I don't always feel privy to everything that is going on in his life.
This evening, as an example, we had all spent the last few days together at our respective families and aldo a great Boxing day, watching the boats sail out of Sydney Harbor. But then, it was time for my son to go home to his dads.
I arrived home feeling totally empty. Thinking, in that archetypal motherly way, that my/our child should be with me/us.
The house seems so empty when he is not here. There is no Lego all over the place (that I usually stand on and curse the fact I have). There is no American wrestling on the tv; we aren't playing WII or reading together; there are no clothes strewn all over the place; no compulsion to make his favored spag bol.
The pretty Xmas tree is still sitting here; the presents I gave him are all unwrapped, but still perched on the kitchen table, waiting to played with when he comes back.
But this is life.
Life for many single, separated or shared parenting households.
This is the decision a couple make whey they (and in our case, totally amicably) decided to part four years ago.
It's just as our son gets older; and I get older, I just think about it more and wonder, is this it?
I am always explaining to him that I have to work because, well, that is what puts food (and Lego) on the table, but that isn't always an easy concept for a child to grasp.
I guess we just make the best of what we have. He has two very 'happy' homes and two parents who love him more than anything and would, with no hesitation, die for him . . . And that, above else, is what keeps us altogether.
Even in we are in separate houses . .
Have you any thoughts?