Could be adrenaline still in your system. I found it hard to switch off after each of my 3 births, running around like I was superwoman, then 'crashed' after about 3/4 days!
Could be a build up of drugs in your system, in which case maybe a bit of a very gentle detoox might help. I'm thinking of you eating lots of veggies, fish, organic meat if you eat meat, drinking lots of filtered water, herbal teas, organic milk, etc... Basically laying off anything heavily processed, chemical or lden with caffeine.
Obviously, if you are still taking pain killers you need to keep up with those, but it could be that they are keeping you awake, so it might be worth talking to your doctor about changing the medication or changing how you take it if that's likely to be affecting you.
It could also be that you are experiencing some degree of trauma, as this CS will have brought back memories of the last one.
Also, you've now got 2 Dcs to worry about, and sometimes I find it hard to sleep just thinking about how soon it's going to be before I get woken up again!
When your mind just won't switch off, the usual remedies really do work:
switch off screens 2 hours before bed (MN as well as TV! 
),
have a warm bath with lavendar oil in it, keep lights dimmed and bedroom cool,
have a warm milky drink before bed.
I also find it really helpful to listen to a relaxation CD or a guided meditation as I go to sleep. There are lots free on the web if you do a search, and you can buy downloads as well if you find one that works really well.
I do hope this passes soon. It really is torture when you can't sleep and you really need to!