I struggle with executive functions as well, but may be not as severely. I often don’t even start something because I learned from experience that I likely will not finish it. I hope I might still have some helpful suggestions that help.
I hate to call people. Especially ones I do not know. My mind goes blank as well. For me it really helps to write down everything I want to say – even the Hello.
An example for a note I take to get an doctor’s appointment:
1. Hello- My name is ()
2. I’m calling to make an appointment, because of ()
During the calls I always try to have my calendar open, so I do not double book. I write it in the calendar the moment I get the appointment, otherwise I will forget it. For the appointment it can help to bring a list with the things you want to say. This really helped me during my first appointment.
Do you have problems setting priorities as well or is it “just” the doing of the task that is challenging?