So sorry for your loss Aggy21, it's life changing.
I hope someone has told you about the Bereavement Allowance, I think the name of it has now changed. I'm not sure if you are eligible or not but it really helped me whilst I waited for probate to come through.
My first advice would be to remember to be kind to yourself, and take each day as it comes. Whether expected through illness or not, it is still a great shock, and you might feel numb for a long time.
My second advice would be to accept all help and invitations, even if you really don't feel like it.
My husband died five years ago. I came back from a beach dog walk and he was dead on our front lawn. He died instantly from cardiac arrest.
I did have counselling as I felt so much guilt and regret. I tortured myself wondering if I'd been at home, if I'd have been able to save him. Looking at the statistics, it is doubtful but the person that found him hadn't tried CPR at all.
A friend told me about WAY UP, a website for widows, and the support from the people on there helped me through the worst, and continues to help me.
way-up.co.uk/
I think the best help I found was this story about grief from Macmillan. It is important to remember our children's grief is completely different to ours.
community.macmillan.org.uk/cancer_experiences/bereaved-spouses-and-partners-forum/f/bereaved_spouse-forum/64421/ball-in-a-jar---an-article-on-grief
Just do whatever makes you feel comfortable, and don't feel any pressure to do anything. I would recommend waiting at least a year to make any major decisions.
As for clothes and possessions, I was under pressure as I hosted all of my husband's family for the funeral and had to make space. I made both of my children a memory bear from my husband's favourite shirts, and sent the rest to bless people at the charity shop. My husband had been in the Church Army and would have been glad to know his clothes were helping people.
In the early days I found it comforting to leave a light/radio on when I go out so I didn't come back to a dark empty house. I still have an electric blanket in the bed, I hardly slept in the first few months. I used to have a notepad by the bed to write down my thoughts when I couldn't sleep at all.
Just do whatever comforts you, grief is very personal. I don't know if you are having a cremation or burial, but some people I know have had beautiful jewellery made with their loved one's ashes.
Take care and keep posting xx