Kazz,
I'm so, so, sorry that you are going through this.
It is not something you can prepare for in any way and you will eventually deal with it in your own way.
I have asked myself all the "what if" questions too, I think that is normal.
I guess in the end though, it was probably nothing you did or didn't do and you can't beat yourself up about it.
Please chat any time you need to, we are hear to help each other and we know how you feel!
I hope you are coping okay and have lots of support to try and get through this.
Sending you lots of :hugs:
Love Layla