My social worker would call this a trauma, because of its contrast to what you were used too.

I am going to suggest we don't always remember traumatic events as we would do normal events, something's seem bigger and more intense.
As a child who was used to being,exceptional it is simply possible you missed some social cues that were going on around you. Especially if you had undiagnosed adhd, you remember these events because they were particularly bad. There may have been more subtle attempts that you just do not remember, because your so sure everything was perfectly fine.
Imho this is unlikely.

But yes, a traumatic event has to be compared against your everyday life.
If you were in a bubble of denial,where the world was perfect and you and your friends could do no wrong. The bubble bursting would be a significant shock.
I hope your able to a dress the issues an make it through.
Take care.