Re: Feeling Guilty about going back to work
I think your fears are normal and it will probably be easier once you have got into a routine with this. It will be good for you to go back to work and help easy the money issue as well as giving you another interest.
Prepare your children in advance and keep it positive so that they will not pick up on your apprehension.
Yes, this will probably be harder for you than it is for them. You are leaving them with your relatives, who have agreed to look after them, not with total strangers. If after say a month you decide that it isn't working, then you would have to rethink the situation.
Good luck and let us kow how you go.