I don't normally read this section and very rarely post a reply so my advice may not be as good or helpful as others' but I thought I'd try to answer anyway.
I'm in a similar situation in that, although our dc sleep well, they are still very young and most of our lives at the moment revolve around meeting their needs: cooking, cleaning, washing, tidying etc as well as of course looking after them and this sometimes means that there is very little time left over for us.
When the dc go to bed we generally end up flopping down in separate corners of the settee, heads in our phones with the TV on as background noise. I admit that enjoy this time as I'm not being touched or climbed on or slobbered all over (I often feel that, when the dc are up, my body is not my own and is instead merely a playground for them if that makes sense).
All this leads to a sense of 'disconnection' (if that's a word?) between me and dh; a feeling that we're drifting apart and that we're more like mates than partners; and this makes me feel like I don't want to be physically intimate with him and as a result our sex life, and my libido, has gone down the pan.
I think the answer is to find a way of reconnecting. Small instances of intimacy such as a smile, a hug/cuddle, a quiet meal enjoyed together, a night or even a weekend alone together (or even a day where the dc are still at their usual childcare) to just chat about anything and everything without constant interruptions.
Another thing could be to take up a hobby, or a fitness class or something that's just yours: time alone, time away from the general day-to-day drudgery of looking after young children, that helps you find yourself again as well as helping you get back to your pre-children body shape.
I wouldn't suggest trying to 'force' yourself to have sex with him; I think that would just feel like another chore that you have to get out of the way and might lead to resentment and more backing away. Bring the intimacy and fun back into your relationship in other ways and you might find that your libido returns on its own.
A very long winded answer, sorry!