Welcome to the forums and thanks for being here. I am sorry that these things have brought you here though, and hope that you'll find Beyond Blue helpful and supportive.
I'm not sure that we can ever 'prepare' for grief - in the same way I don't think that we can prepare for heartbreak, or falling in love; the feelings can come with intensity that we might not expect, and there's no way to really know what we might feel. I think it's also important to know that sometimes people can experience 'anticipatory grief', which is like a type of grief before someone dies.
With all that said though, you have asked for some resources, so I'll try and share some here
- Find some things that give you comfort and routine
- Be open to getting some extra support or seeing a counsellor. You don't have to wait for this.
Here is a free resource that you can use anytime: https://griefline.org.au/get-support/
- Do some journalling, or find a way to express how you're feeling. There are also grief prompts and grief journals that can help
- 'It's okay not to be okay' by Megan Devine. Her blog (refugeingrief) might also be worth looking at too. I especially like her because she emphasises that there's no timeline or right way to feel
- 'On Grief and Grieving' by Elizabeth Kubler-Ross. She's the lady who talked about/invented the 5 stages of grief - I've especially liked it because it just normalises so many of the feelings and how unique grief can be for everyone
- Validate validate validate. Whatever you're feeling, it's okay