Hi
It's a steep learning curve, for sure. I likened the early days of my diagnosis, surgery and treatment to getting on a train, thinking it was going to stop at some nice little village stations only to find I was on an express train hurtling to the other end of the country. The information does sink in eventually but it takes time.
Hopefully your Mum will feel much better once the drain is removed tomorrow. I had drains in too and felt much more normal once they were removed.
I see from your profile that you're in the US, is your Mum being treated there? I guess some of the practicalities would be different to the UK given that health services are organised differently.
All the best to you and your Mum.