Hi Minkulus,
Have just read of your loss, and am so sorry to hear your sad news.
You sound like a strong woman and a wonderful mother. You are doing wonderfully well so far.
My DH died at the beginning of this year so I am recently widowed myself.
I have been surprised at how physically exhausting grief is; please be very, very kind to yourself; eat and drink well; try to get to bed even if you can't always sleep as you will be resting; do as much as you can, then try to rest.
Accept all help that is offered: cooking, cleaning, anything that will support you as you support your children, and yourself.
Keep things simple.
Don't make any major decisions for at least a year.
Make sure you apply for bereavement allowances; there is a special department in the DWP which will take you through the process with kindness.
I have good days and bad days; on bad days I concentrate on getting through in half hour slots. Every day is different so far, but I'm still here, and you will get through too. 