@BowerBird11, everything you said I felt as I'm sure most people feel when they receive the news.
I was diagnosed Dec 4th 2018. When I look back, I'm glad the days were so full as it was distracting and like you I was exhausted. Once treatment starts, it will at least feel like you are moving in the right direction and you may feel better then.
You can be honest here, we all understand and can relate.
A year down the track with my active treatment finished, I feel closer to the old me but I am different. Don't hesitate to get some counselling if you feel you need it, it has been a godsend for me.
Just know that we are all here for you if you need some moral support, have a question or just want to vent <3