I\'m feeling really bad today

I've crashed today, knew it was coming, could feel it slowly building up and then it broke.  I don't know what to do now.  All I ever hear from people is how I could do things better, how what I do upsets them, how they would prefer it if I did it this way or that way instead.  Life isn't easy, there aren't instructions.  I'm on my own now with 7 young children to care for since my ex walked out 8 months ago and I'm trying to get through each day as best as I can.  I'm sick of hearing about all the bad stuff, I try and do what is best for everyone, I can't do everything and no one wants to help me.  I couldn't even do much today.  I'm really tired, emotionally and physically.  I just want to sleep.  I have no family support, I do it all on my own because I have no choice.  I just don't want to deal with the world anymore.  I want to be left alone, I want to be invisible.