If you are under the 25%ile (which is the lower number in the mid-50% range), I recommend you not submit the score.
I don’t think you need to apply soon, but IU is rolling admission (so, for example, if you apply in September, you may have an admission decision by Nov). The EA deadline is Nov 1 and you should make that (again I am giving you recs in a vacuum and don’t know so much about you and your app).
You should talk to your HS GC. Have you requested at least one letter of rec from a junior year teacher? Does your HS use Naviance or Scoir (software packages to help with admissions process)?