You cant see my pain

I laugh to cover my heart ache,
i smile to cover pain,
you look into my eyes,
yet you cannot see the strain,

when your in pain,
I'm the first to see,
but you cannot see the heartache,
thats controlling me,

you cannot tell the difference no more,
from when I'm happy or sad,
because you never see me smiling,
you only see me mad,

i don't know how long you can stick by me,
i don't know when you'll see,
i just need a helping hand,
to set free,
a dying me.