Indeed it is, and thankfully that is not something you currently have to manage.
Perhaps. I have not heard this, nor do I have this experience or know of a child diagnosed so young who does. I only know a limited population, of course, but I do know of several children and not one has this issue. My son was diagnosed at age 3, has certainly had some lows, but nothing that has impaired his ability. He graduated from 8th grade last year with the highest GPA in his school and excels in areas outside of academics.
There are too many examples of people, including children, and even toddlers who are leading enriching, fulfilling and wonderful lives for you to ignore. I urge you to look around, focus on the blessings you have, manage the challenges you currently endure, but please, stop wasting energy on challenges that have yet to and may never come.