So sorry to for your loss @LlamaGiles ,
My DH died very suddenly at home 4 years ago it was absolute horrific I had to call the ambulance and police ( always the case when someone dies at home apparently ) and deal with the guys that came to pick up DHs body I honestly dont know how I got through that , my DB got to my house very quickly and helped me but god it was hard .
Everyone is different and copes in different ways but the following things helped me
First couple of days -
Got my DB to tell family but made sure he told them not to come round until was ready .
DB also told my boss and sorted out my bereavement leave between them.
DB gave my local take away £30 and told them to take some thing small but tasty to me every evening ( They found out a few days later why he had asked for this and refused to take payment for 7 days )
Eat what ever you want , diet and sensible eating can take a hike for now, its more important that you eat something rather than worrying about its nutritional value .
keep a note book close at hand , write down anything you want to remember , it can be DH memories , shopping list , what to ask the hospital / docs . I wrote how much I hated him him for leaving me with such venom I broke several pens but it was good to get it out of my system
Get plenty of copies of the death cert , I ended up needing 10 !
Next week -
Monday get in touch with the banks you use , most have a bereavement section on line or if you feel up to it go into a branch .
They can help with stopping and direct debits / standing orders for things you dont want ( subscriptions to clubs / magazines etc ) and help you sort out any payments that you may struggle to meet . I am with the RBS , they were fantastic
Have a look at this www.gov.uk/after-a-death/organisations-you-need-to-contact-and-tell-us-once . unfortunately it wasn't available in all areas when I needed but hopefully it will cover your area .
If you cant use it you need to tell all the services that were in DH's name ( gas / electeic / tv / sky / water / car insurance / council tax etc ) and transfer them to your name but there is no real rush for that.
Remember you will be entitled to 25% discount with C tax
Later in the week get this benefit sorted , www.gov.uk/bereavement-support-payment
it is very easy to sort out and is not means tested in any way , it was a god send for me .
Dont cut yourself off from people , I just wanted to hide from the world but it did not do me any good at all .
Let people help . .
It will be very hard but talk to your DD about how much her daddy loved you both , keep his memory alive and if she acts up m remember it is just because she is very young and wont know how to express her grief.
Ask for recommendations for funeral homes and consider whether it will be a burial or cremation.
The service is for you, DD and other very close family members friends will have to take a back seat , they can be hard to discuss so write down what you would like , ask others to do the same and try to find a common ground , dont let it become a shouting match or one-up-manship
Keep asking us questions , many of us have been through this and will be able to advise
Keep talking to us on here , we will be here to listen.