Complicated family relationship...

Yesterday night i cried for the whole night.
My heart feeling damn painful because i saw my mom cried there also.
I am sad because I can't really protect my parents.
I still can't give them the best thing let them having a better life.
I am working hard now to achieve the goal that I set for them.
But in this long term period, my family facing a problem.
All my sister never take care of my parents.
They treat their friend even better than treat me and my parents.
This make my mom so sad.
My daddy do everything for family.
He working hard and save all the money to give us a better life.
At outside, he so less to having meal because he said that the meal outside was so expensive.
Even though a plate of rice just for 3 or 4 dollar, he also feeling expensive.
This make me feel more sad, I feel myself so useless.
My daddy and mom do everything for us.
But now they didn't get back anything from my other sister.
I don't know what to do.
But I had told my parents that don't worry no matter anything happen, I will take care them until they elder for their whole life.
Just because they are my lovely parents.
And I also feel lucky that God send me a lovely present - my lover.
He giving me a lot of support.
Dear, just want to say that I am lucky to be with you.