GED, High School Diploma, and Transcripts
If you went to a Yeshiva where shaving your beard was allowed, then you might have lucked out. Your Yeshiva may have been accredited with the state, and your Halacha classes might have counted as high-school hours or even college credits. Litvish yeshivas sometimes offer an accredited high-school diploma, and some even offer up to 30 college credits to transfer towards a degree.
If you went to a Satmar, Belz, or Chassidish institution, then you are out of luck. First off, they are not state accredited. Second, they will do everything they can to avoid handing you any proof of your attendance. Third, they might go so far as to hand you a crudely drafted document with falsified grades so that you come across as a failing student, and hurting your chances at getting into college. Do not try to haggle or bribe or negotiate with them for a transcript. It is nonexistent and they will only aggravate you and cause you pain and frustration.
Take this time to look ahead rather than grieve your time lost. Find the help you need in order to take a GED and get a real high-school diploma like you deserve.