You were "going about 85-90" then you were accelerating?

Normal roads with undulations in them can do strange things to you at high speeds. Before your car can finish reacting to one dip or irregularity, it can be into another one, setting up situation where traction is unequal and you lose control if you do something wrong at the wrong moment, particularly if you are not going straight. Were you familiar with the stretch of road? Was it interstate or other hwy?

Don't make the same mistake twice, you might not be around to post about it next time