Very well done. I have a suggestion - The rhymes are there, but you don't need to lay it out for us so clearly. The way you have it now breaks up the lines - and the thought. For instance, you could write the first verse like this, and still maintain sense and rhyme - and it sounds more conversational:

Tonight I wanna cry
And let these teardrops burn my sheets
I've always been weak -
I try not to live life in a lie
But pain is always welcome
And it greets my heart so eagerly
Embracing all the happiness I'm facing
And then the war begins

This is really sad, yet beautiful in the way you expessed such feelings. I believe that many can relate to this piece. I like the last line too, it really summed it up nicely...

Sarah Sweet Sarah, let the tears flow cry a river, never regret always learn from. This piece is sad and heartfelt, written beautifully and I'm sure many can relate to it. I love it just the way it is....

Very emotional and heartfelt poem. Nice way to express the feelings... Good poem indeed!