It's so difficult

For anyone who is bereaved or no longer providing care.
Ian, I'm going to say something 'odd'. Relish this time. It is your time of saying 'goodbye' to your mother in this life, and that has to be a good thing to do. Remember as much as you can, all the way back. Write her a letter if you wish. (I wrote one to my mother, and I wrote loads to my husband!).

Sit and 'be with her'.

Whether our 'spirits' or whatever linger, if they exist to linger at all, our memories are certainly powerful, and our emotions more so.

I always say 'our tears are our tribute'......

Your mother may not be alive any more - but her love will last you a lifetime. You'll never be without it.

Kindest wishes, at darkest times, Jenny
I agree with Jenny (we are both widowed). Remember that on the day of the funeral, you will be one of the Chief Mourners, saying goodbye to a loved one. I asked the funeral director to tell me where to stand, what to do, so I felt shepherded throughout. The day won't be as bad as you might imagine, as the others attending are there for your family. (Be sure to take a bottle of water to leave in your car, so you can have a few sips after the service to help regain your composure).
I can totally relate to this. I just lost my mum recently. The "hit you like a train" is how I describe it to others. My mum pretty much died in my arms as well. It's incredible painful. An unimaginable pain. I feel your pain x