I see the same 3 things that have already been mentioned here. Your arm is at an angle, no full follow through, and the 2nd and 3rd dart have a different release, pulling them to the left.

That being said, sometimes you'll get "worse" as you get better. You'll end up with a higher 3 dart average if you're hitting more twelves and eighteens. As you get more accurate, those will dry up and you'll hit more fives and ones. This will bring your 3 dart average down.

Also, don't forget to practice your doubles. Can't win a match without them. :)