I agree, you can will yourself to be good.
But, look at your original post and you can see that your pacing is poor, as you died bad in that race. It means you simply aren't in good shape. Run more. Then run more. Then some more. Be mindful of injuries along the way.
If you go to the track and run one lap at 5:45 pace you can likely do it comfortably, right? In reality, that isn't all that fast. The trick is being able to hold the pace for a very long time. The more minutes you run and as you get older, the longer you will be able to hold the pace.
Another way to think about it is, right now, how long can you hang onto a pace that would get you on the varsity? It sounds like it is about half the race. By consistently training and running more, you'll see that move upward over time. Just stay with it. It takes months and years, and the beauty of this sport is anyone will to put in the work will get a LOT better. Not everyone will be a star, but everyone can get a lot better.