I would echo what others have said. If you have tried going out fast, and the result is typically dying in the 2nd half, I wouldn't expect success to come from trying a sub-optimal strategy again. If you're the 6th best of the 6 person lead pack, why not try trailing just off the #5 guy in that pack, and choose a point in the race to try to attack him - perhaps at the 1.5 or 2m mark. I agree that you don't want to be stuck way back in no man's land, but sometimes running 5 seconds slower in the first mile can be the difference between feeling stretched vs feeling quite comfortable. Start with a reasonable goal - finishing 4th or 5th in stead of 6th. If you race to that strategy, I suspect you will perform better than you have been. Then, if you race to your full potential, you just might be surprised to find yourself in the right place at the right time one of these weeks and have a shot at top 3 or better.
Another consideration to throw into the mix, is whether you have a sense to which you have outperformed or underperformed your fitness (as measured by workouts) so far this season? If you have underperformed, it could well be that you are going out too hard in the first mile. You might be due for a breakout race if you deploy better tactics.