Returning to the main topic of discussion... Why not translate "I want to become what i am" as "я хочу стать самим собой"?
And don't confuse "суть" in different contexts. There is a number of homonyms: "суть" as essense (of a problem), "суть" as 3rd pl of "to be" Аз есьм, ты еси, он есть, мы есьмы, вы (еще что-то), они суть.
So ist es.