I so know the feeling.
BUT
it will pass.
Having small children is no joke and having small children, being tired and having a mate who also drained can get on the nerves BUT
it will pass.
Don't do anything too hastly, try to take it in stride.
One day you just wake up refreshed!
This means one of the following:
1- This is not the life you wanted, ie leave everything.
2- The children are actually an addition to your day, making things more interesting, more fun, rather than sucking the life out of you
3- Dude has to go since he's been holding you down for too long and you and the kids are better off
4- Hot diggity, it was just a phase, life feels lighter and DH is suddenly reminding you of the reason you got here in the first place(now compose yourself and enjoy until them teenage years hit)!
Any which way, it alls gets better.