I don't mean to discourage or dissuade you from your quest, and I haven't listened to your clip, so this is just a general comment.
I really think that it is almost impossible to reach actual native pronunciation level if you're an adult learner. Near native would be a much more realistic possibility, and even that would take a long time and a great deal of effort.
I do think that clear pronunciation is important, but so are other aspects of learning a foreign language. I say this here as I note that your grammar can be improved too.
Student or Learner