Go back to Rolamia and finish high school there instead of taking the GED. The GED exam series is not easy, it is designed for students who dropped out of the US system, and is considered to be the equivalent of a basic HS diploma. For college admissions as an international applicant, you want your high school record to be more than just the bare minimum.
Don’t come to the US with the FLEX solely in order to improve your admissions chances at colleges in the US.