I have a stressful situation coming along in upcoming days.

Almost everything is beyond my control and even when the outcome is known and in my favour, I am mildly stressed because of uncertainty of time.

How do I remain calm in this situation and muster up courage for the person whom I have to support dearly?

Things I have tried:

1. Breathing and calmness exercises
2. Diversion of thoughts
3. Talking to friends/family

Things I have prepared:

1. Booked a therapy session in advanced
2. Asked friends and family to be on stand by for emotions support
3. Built an inventory of motivational stuff
4. Gathering threads and articles which can help me get through
5. Completed office work so that in case I go low, I can focus on what's important and urgent

What else I can do to not feel unnecessarily anxious given that I have zero negative thought or vibe of the upcoming situation?