I definitely agree with everyone else, just keep practicing. I just started too and the two things that helped me tremendously are:
1. Use a jumbo salon clip -- like this one: Salon Care - Jumbo Plastic Clips
-- to hold your bow together while you tie or sew it off. I could NEVER get the crease right, and once I got these, I just wrap the thread around the middle of the bow inside the clip and when I pull it tight, it makes a great crease.
2. Try to make a template. Or, you could buy one of the ones people talk about on here, but I didn't want to spend that much money on something I wasn't sure I'd use. I made several like this: Hair-Hardware.com - Show Some Love - Make A Bow
(but out of a flexible plastic cutting board instead of cardboard so it would hold its shape better). With the template, all the loops always come out even.
Good luck, and if it makes you feel any better, I really don't think your bow looks that bad at all!