How can i become a better coach?

so, im 16 and teach two different learn to skate classes one is a teen/adult and on is little kids. alot of the coaches say that im really good and ill be really, really good in a few years. im being mentored by a national level coach, so i know what im doing. however, in the past couple weeks i feel like ive been to firm with the teen/adult class. i dont yell, but i have firmness in my voice. they say that they always have fun in classes, but i feel like im being to firm and its coming across as slightly mean/strict. there is one guy that ive had for a while and he always acts like i dont know what im talking about. i try to explain it nicely, but he always grimaces when i try to correct him. my mom said that today she was embarassed because it looked and seemed like i was being mean to him. after a while of the way he treated me i kinda snapped. i feel really guilty about it and want to know how i can change it. so, what are some good tips i can use for being more relaxedx and not strict and becoming more nice and patient when theyre learing new things?