Rejected by fellowships, worrying about my future
Most physics graduate students at MIT (and elsewhere) are not supported by fellowships.  Certainly, a fellowship would not hurt, but whether or not you get a fellowship will have very little impact on your future career.  What will matter in the long term will be the quality of your research.

As a graduate student, both your research output and faculty members' evaluations of your research skills will be important.  As you advance further, it will be your personal research quality that will most matter.  Other factors, like the quality of your teaching and presentation skills, will affect whether you get good jobs, but whether you had a prestigious fellowship in graduate school will be basically irrelevant.