1. If you don’t like goyim, try Olam ha-ba – not goy free but less of a problem. The world is full of goyim. Live with it.
2. You can schedule your own classes. No one assigns you to a specific class is college.
3. Unless the assignment was given Friday afternoon due on Motsei Shabbos (very weird, professor don’t work then either), you can always do your assignment early.
4. The rest is covered by the “reasonable accomodation” rules from various state and federal civil rights act. However you do have to ask – in advance and as early as possible.