Your reactions are typical of a new student of meditation. As far as sitting on the pillow it is traditional but not needed. Yes, you are being told to sit in a certain way because proper alignment of the body is needed to breathe freely. Meditation is ancient, thousands of years old, and the various techniques are there for a reason. It sounds like your ego was getting in the way. That is exactly what happens when first starting meditation. The ego and the "me, me, me" part of the self starts clamoring for attention. Meditation is designed to cut through the constant demands of ego. Meditation is a discipline, like martial arts. I am not sure why you were there. Maybe you aren't ready for the discipline of meditation and should try some other kind of class such as an art class or a yoga class.