1996 Ford Bronco, Shaking at high speeds (65+) and making noise when coasting

I have a 1996 Ford Bronco that I bought in mid August.  Lately I've noticed
that when I drive above 65 mph, the vehicle starts to shake.  not so bad as
to make me fear its going to fall apart, but enough to make me stay under
65 when i can and not go above 75 if at all possible.  yesterday I noticed it
also shakes around 55mph, then stabilizes somewhat at 60 and still
shakes above 65mph.  The most pressing and worrying issue is that if I
coast at or above 65mph, there is a terrible grinding noise and the car
starts to shake until I either give it gas or reduce speed to under 65mph.

Any Advice is greatly appreciated.
P.S. this is my daily driver, and since I am in school I occasionally drive it
long distance.