All I can offer is my support and also let you know I am in a similar boat.
I think all you can do is be there for them. Its hard not being able to discuss their needs with their father and its devastating seeing them upset but its better than arguing with their dad all the time. Its also easy to get bitter about all the water you have let go under the bridge
Its really important not to let your feelings about their dad known to them. I am sure you know this, but its amazing how many mums i hear slagging off the kids dads within earshot. Let them make up their own mind.
Treat your kids when you get them home, give them your undivided attention while you bathe them, watch a dvd, read to them and cuddle them. they will be tired from the journeys and change of diet and routine.
you are welcome to PM me, I am new here and seems like we are in similar situations, although I dont have experience with family court. not for want of trying my boys are now 11 and 12 and i am feeling the full effects of going it alone for so long
How have you felt with the new arrangements? I was always so grateful of a break, and i think the boys were too, but I worried a lot too and could not stay in the house alone for many years.