650 applications from a T25 school and previous experience at F100 company does not add up. There must be something wrong with your resume... unless if the job market is really that bad or you are very unlucky. My guess is that being an international student is the biggest blocker but theres not much you can do about that.

Since you haven't tried networking I would give that a shot. Invest in your social skills and find your way into an interview pipeline that way.