In the middle of unable...

Trying to be strong, but it's not as easy as I think. Trying to be cheerful everyday, so that people won't know that I'm struggling inside. I'm doing my best, just like the Bible has said. But still, I feel so tired to continue. How can I move on with such problem? What I want to do now, is just stop and go to bed and pretend that I'm the only person in this world who trying to relax and imagine many things and dream about good things (of course this will not happen, with one 2 years old baby in your house, which very depend on you!).
I stand in my door right under my star fruit tree, my eyes are looking outside and starting to sing in my heart some songs that can encouragement my soul. And I begin to talk with God:
"Lord, I don't want this thing stop, because I know it will not happen. What I want from you now, is give me a new heart. A heart that can thankful for everything, a heart that helps me to have a positive perspective about life, a heart that never give up from challenge, a heart that make me closer everyday to you, a heart that can please Your heart as well... Thank you Lord"