ENGLISH GRAMMAR IN USE は 誰が何と言おうと本当に良書です。
（実は米英語版のGRAMMAR IN USE ももっているのですが中身みてません
800 is quite an achievement.
I think your success is all the more inspiring because it didn't come easy.
Since you embarked on TOEIC studies, there were many obstacles.
You often had to find time to study after a busy day of work.
And despite that, your scores went down earlier this year.
It is how you reacted on such occasions that makes you a true TOEIC hero.
You never gave up, and just kept on going.
Now you have the result.
But I'm sure this is not the end for you.
It may not be the TOEIC or Eiken. It may be something completely different.
But whatever you may do, you will continue to be what you are: a hero.