Go to a emergency psychiatric unit.
Your illness is making you think like this, it is a form of psychosis in a case of severe depression where you start to believe that this action could be a solution.
It is like jumping from a burning building because it is better than staying where you are, but you cant do it, you have to go to a hospital.
M4 is right, suicide may be the beginning of something worse. You need to seek help and you shouldn't even be considering murdering your children, and that's what you'd be doing!!! It's times like this when your love for your children should be driving you to get better so they can have a mother and a life. If you feel you would miss your children, how can you think of hurting them? You should stand strong and fight for your life and for them, they deserve this much. Seek help immediately and give your children to your husband or relative until you are better. You would not be saving yourself or them, do not drag them down with you!
Hang in there, your situation is curable and therefore reversible. You must report to the hospital as soon as possible. If you think about suicide and taking you children with you the wise thing to do is to call 911 before it's too late. Your children doesn't deserve to die, you are not bringing them with you, you will all go away if your are dead. You can believe in life after dead if you want but this is not scientifically plausible and even if so they don't want to be dead. Don't project your situation on your children and seek help as soon as possible. There are many solutions to many problems. Death is not a solution, it's an ending. If you want to repair a shed, you don't burn it.
M4