First off, it's very good. :3 Your piano playing is exceptional. And the fingerings you used for this work perfectly, so none of it sounds awkward.
Now, when you sing "and I need you, and I miss you," it's a bit out of tune. I want to say you're about a half pitch sharp there. Now, when you hold notes, use vibrato, otherwise it'll come out off-tune as well.
This part is just speculation: When you write songs, or even make arrangements of them, all of the instruments as well as the voice should be able to stand-alone -- without any other backup -- this works with your piano, but if you were just to sing, I think it might come out rather odd.
But still, it's a very good job, and I hope you don't take my critique too harsh. <3
