Is teaching for me?

Been feeling lost ever since I stepped into the education service.. Now and then, feelings of pessimism will wrapped me up, sometimes so tightly that I can't breathe. There is no particular reason that I can pinned down to. And this is what scares me so much.. I fear that I can't teach well, can't interact well with my colleagues, can't meet the school's expectations but nothing beats my worst fear; QUITTING. I really love my job but only one aspect: my children. Nothing is as fulfilling as seeing an unhappy child smiling at my goofy jokes, seeing an unmotivated child finally working for a goal after my incessant nagging... The link to a child, that reach to a child's heart is as close to heaven. But Im so afraid I will lose this passion, this battle to my fears.
I wished someone would understand, someone would look beyond the mask I wear everyday to work and tell me how I should "go". I really envy those colleagues who are so happy and contented in their jobs. I wish I coud find my contentment soon.. I really hope so..