i think it is harder on the muscles riding fixed, and it's probably likely that you were much more tense than normal on account of fear of death. you will loosen up as you get the hang of it and i urge you to stick with it. the naturalness of fixed is much more natural than the chaos of freewheel.
if it's any consolation, i stuck a freewheel on my old fuji the other day so that i can sell it. i rode it round the park and found it so odd to not be braking with legs, especially at low speeds, and the whole thing was so unsettling that i flipped the wheel after about three minutes.
i think it is harder on the muscles riding fixed, and it's probably likely that you were much more tense than normal on account of fear of death. you will loosen up as you get the hang of it and i urge you to stick with it. the naturalness of fixed is much more natural than the chaos of freewheel.
if it's any consolation, i stuck a freewheel on my old fuji the other day so that i can sell it. i rode it round the park and found it so odd to not be braking with legs, especially at low speeds, and the whole thing was so unsettling that i flipped the wheel after about three minutes.