Oh dear, you sound like you are at your limit with worries! I am so sorry you are struggling with the results of your fall.
I think for now, you will need to wait to hear back from your surgeon's staff on how to proceed. I doubt you will be the one making the decision, the surgeon will lay out what you can expect and then proceed from there.
I can be guilty of this very same thing, so can only advise you to try and stop worrying and building this up worse in your mind than it is. I do this by diverting my mind to something else, even if it's counting flowers on the wallpaper! If driving I look at the patterns of the tire treads on the car in front of me.. that sort of thing. Believe it or not, it can help turn off the downward spiral of my thoughts.
Can you make a list of questions for when the OS office calls tomorrow? It's always best to be prepared..
Is there a possibility of in home care after your surgery? Home health nurses or aides to check in with? That would be one of my first questions if told that the surgery is okay to do.
Who knows how long you will need to wait for another appointment? That's another thing I would have on my list if they want to delay.
The good news is that you will be resting more immediately after a THR and that will help your coccyx to continue to heal. There aren't any exercises that are necessary in a THR recovery, plus you will have some pain meds to help you cope. The main instructions that I had after surgery was to get up hourly if possible when not sleeping at night- which is a bathroom break and while up to try to walk 50-100 steps which helps with your circulation.
I opted to rent an electric lift chair to have in my home for the first month. This could be very helpful for you in getting up and going out of the chair. Something to think about.
Again, so sorry you are feeling so stressed about this.
Your surgery date isn't for 3 more weeks, that's a lot of healing time for your poor tailbone.
Hang in there, either way you will get through this.