I'm really sorry for your pain. Probably the best thing you can do is for you to find a professional to talk to about it. You need someone non-judgmental and in a secure setting who can listen and help you through this tough time. There are services that adjust their fees on a sliding scale if you don't have enough money. Keep in mind that you are grieving, no less than if you had lost your family in an accident. Be gentle with yourself and try to make sure that you treat your body well. Get plenty of sleep, eat well, and stay away from drugs and alcohol because while they may dampen the pain in the short run, in the long run, they make it worse.
Do make sure that you arrange to see your girls on a regular basis and keep touch with them even when you are unable to see them. If you are in a position to care for them, perhaps you could consider filing for custody of them, if that's what you want. (...and it's easier to do before they've left the state than to demand that they be brought back).
I wish you the best.