Did you have lined bifocals? Or Progressive lenses? That is, was there a definite line in the lens where the prescription changed, or not?
Typically, the Progressive lens can cause that seasick feeling. People who are going directly from no glasses to bifocals do better at learning to wear them.
People who have lined bifocals have the toughest time transitioning to Progressive lenses.
Those who have single vision lenses fall somewhere between them. With many doing better with lined bifocals.