CURRENT EDUCATION SITUATION (i'd like to recieve as many comments as possible as I am stuck in life)?

I came to the US illegally at 3 years old and i am now 17 years old. I am currently a sophomore in high school (retained in 7th grade because of absences) and my grades and absences are an actual disaster at the moment. There is nothing i can do to help bring my grades up and I am guaranteed to be retained again so I don't know whether to finish highschool in a 2 year program at some adult school here in the US and get my high school diploma, or return to Mexico and finish highschool education at a private school. Nonetheless I plan on going to college in Mexico. I just dont know where I should finish my hisgh school education. THANKS IN ADVANCE