it is understandable feelings, and it is not uncommon

your experienece is not uncommon, many have similar experience, to certain degree. People with claustrophobia (with or without knowing about it) would feel uneasy in the enclosed space. MRI also could trigiger some inner ears fluid flow, according to some researches.  Some people with inner ears balance problem, or motion sickness conditition may experience dizziness and/or nausea during the procedure.

next time, ask for more open MRI device.. which is a little better.. also with more experience, you will feel better.

for those who laughed at his experience, consider yourself a lucky one who can go through the procedure without any uncomforbable feeling. But people are different, individual to individual. When things don't happen to ourselves, it doesn't mean that those things don't happen to others.