You....mom?

my old teacher is my birth mom

I never thought It could be you.
I never thought you was my mother.
 For years for years I never knew.
I thought bout it but didnt know was true.
 How could you not tell me.
Why...why.
 I dont if I should be mad or happy.
 I know I said you was like a second mom to me.
But I didnt figured you was my birth mom.
 Ive known you since 6 grade.
I guess I cant get mad, you've always been there for me been to all my games and all.
 Always been there to wipe my tears away.
I guess I cant stay mad at you.
Least you been there for me growing up.
 Still dont quite understand, but im sure you'll help me through as always.