Really feel for you, Sinkingfast. Prett yclear already on this thread that plenty of people struggle with their DHs in a similar was, but it sounds like there are some other issues between you and your DH.
My DH is also a great father, but not in the way I had hoped my DH would be, IYKWIM. Does things when HE wants to, and doesn't thinl he should scacrifice his own desires for the kids. Example: he said to me the other day that he was happy to kick a ball around the park with DS for 20 mins but "I'm not taking him to the swings cos I find standing around watching him climb up a climbing frame for the 20th time so effing boring" Like I find it really fascinating! He just doesn't seem willing to put himself out in the same way I am.
On the one hand, I think if I had to commute and work hard all day, maybe I'd want to use my time off how I wanted too. On the other hand, I think FFS, he has his breakfast and lunch home made and given to him, dinner ready when he gets home, and once he's home that's it for the day. I, on the other hand, have to cook, clean, feed the kids, get up 5 times a night with them, and it never ends from dawn to dusk. And then DH complains about the "state" of the house!
I'm going on a bit but just wanted to say I think a lot of men, though essentially decent blokes, can be bloody selfish and thoughtless about what it takes to look after young children and run a home. And three under 5, well, I take my hat off to you.
Bottom line is, taking the parenthood element out of the equation for a second, is DH someone you still want to spend time alone with? Do you LIKE him? I think as mothers we can become so entrenched in our roles as wife and mother that we sometimes lose touch with our "former selves" and the basis on which we fell for DH/DP in the first place. Of course parenthood changes everything, but I'm just thinking perhaps if you can get back to that personal connection with each other, you can rebuild things from there?