Any particular reason why it is so big? Is this for fun, or is this going on a website, 'cause if it's just for fun, shrink it down quite a bit.
As he says, this is way too big...
When just starting out, it's much safer to start with smaller sprites... On a smaller scale, less looks like more.
Once you start getting into really large images, it takes massive amounts of patience and skill to achieve the same effect as can be achieve on smaller scales.
Here's a quick GBC I made for you to (hopefully) learn from.

As you can see, it fits inside yours' screen...