Though it's nice fan fiction, and a good writing exercise, it usually doesn't pay to write a spec script to a property that you do not own the rights to.
The only time it seems to work is if you're trying to get a job in television, which you have. But for features, probably better to write something original that you can pitch.
Of course, there's a lot of new Star Wars side movies being produced now, perhaps an SW spec script might get you a job writing one. As long as you have an agent, and I assume you do, you can get someone at Disney to look at it.
Which is a lot more I can say for 99% of us who neither live in Hollywood nor have an agent!