Oh my dear Lady,
Pls don't be so hard on yourself. You are dealing w/ SO much and trying to take care of so many things. I give you credit for still dealing w/ all of these things.
I have a BIG wall calendar in my kitchen, I make ALL my phone appts while I'm standing right in front of that calendar. I write down who (there's my DH & me) has appt, which dr, lab, etc. and the time. I have all our appts listed on a 'list slip' that I got at Michael's, it is always in my pocket book. I have it broken down into the next 4 months. I use this to keep myself current when we are at the drs making a new appt. I write it down and I get an appt card. As soon as we get home, I put all info on the BIG calendar in kitchen.
If my DH makes an appt from home, he calls from the couch in our LR. No piece of paper or calendar. Tries to remember who, when, where and then tells me so I can write it on the calendar. I have had to call back those offices and get the info from them, as my beloved forgot key info. Obviously, he and I have way different systems.
I have a dr's office that has the world's worst secretary. She changes appts and doesn't feel the need to share that w/ ME. Then gets annoyed w/ me for showing up on the 'wrong' date. And yes, they call a few days ahead to remind you of appt. DUH.
All you can do is your BEST. I think you are doing a tremendous job. If they don't understand, they honestly shouldn't be in this line of work.
God bless. Alice.