Considering I literally pulled a Google Translate, I expected to be wrong. Thank you for correcting me! And if your wondering, Imma flesh this out into a murnoesque Worlda, since I am much better with them than I am with maps like the one I made ^^It's always good to see an Estonian AH! A few corrections to your text:
"The Üdassi" should be "Üdassid", as ethnic groups are always in plural.
"extinct people" should be "väljasurnud rahvas" (the word "inimene" is closer in usage to the word "human").
"in twenty years" should be "kahekümne aasta pärast" (literally "twenty years after")
The end is pretty decent, but in this kind of sentences "you" is moved after the predicate for emphasis. So "mida teed sina, et aidata" ("sina" is a longer form of "sa", also more appropriate in this case).
So it should say "Üdassi on väljasurnud rahvas kahekümne aasta pärast; mida teen sina, et adiata" or "The Udasi People will be an extinct people in twenty years; this is happening, what will you do?"