My car has a very bad vibration where it shakes not only the car but myself as well from about 35 mph up until 60 mph. This happened when I just got on the interstate and when it started vibrating, I thought it was a flat I pulled over and nothing was wrong. I got back on the interstate and it was doing again I punched the gas pedal down and when I got up to about 65 mph it leveled out where it wasn't vibrating. When I pulled into work parking lot and got out of car it had a burnt smell like the smell of an emergency brake if I was to leave it on while driving. The ER brake was not on so I wouldn't think it would be that. Can you help me with what you think this may be?

Thank you.