I am dejected

I come back my country about 6 six months already. Also I got a favorite job that teaching children at kindergarten.
I am so tired right now, that was from my mate, working with me at school. Sometime I feel disheartened because my mate didn’t want to help me to care my children of my class. I don’t know why, but I think we are working together, so we are partners, we should help each other.
I don’t complain with my class that I have fifteen students in my class, it is about half of kindergarten.
I prepare breakfast on this month and clean floor every day. They just have 6 students and 8 students. They have a lot time to do some thing for children. They just want to tell me, I need to clean bathroom, even though I am care children at same time, they still call me to do another thing, but they just talked together.