I used to mark every date and every year a bit like @Purplependant222 said after my dad died in relation to what he’d missed out on. He died when I was a child so also missed all of the milestones in my life from O level results to my degree, marriage and becoming a parent myself.
I was much older than you and it must be very distressing not to remember your mum. My dad was a total workaholic and I didn’t have a terribly happy childhood. Although he was there, I didn’t really know him. And he didn’t really know me either. Not as my dd knows her dad for example. I have so many blanks in my memories. It’s not the same, but I do get it to some extent.
I do agree with people saying you’re setting your dh up for failure. I had counselling after my dad’s death. Then more, then more until finally I found a decent therapist, who set me free. As a result, I no longer painfully lament over what was lost for that is not my burden to carry. Neither is it my dh’s.
From what you have said, I would be concerned at the effect this is having on your children. Trans generational trauma is very real and was passed down from my mother to me. I, of course, bought into the trauma as a child and as an adult into my 40s until I had decent therapy. So for this alone, I would urge you to get some therapy to get past where you are right now so as not want to pass this pain and burden onto your children.
What therapy did for me was to allow me to parent myself. I healed me by being the mum to me I needed. Perhaps you can do this too and this will enable you to live your life the way your mum would have wanted.
I know some posts have been very harsh. Do try to take the learning from them when you are ready. As someone, who was at the receiving end of an emotionally fragile and damaged attention-seeking parent, I felt very controlled. And still do now. I imagine this would not be something you would want to pass on to your children.