Your toughness is made up of equal parts persistence and experience. You don't so much outrun your opponents as outlast and outsmart them, and the toughest opponent of all is the one inside your head." - Joe Henderson
The Logic of Long Distance
My sport's your sport's punishment
100 Km month 150 K month 200K month
5K run 10K run 20K run 30K run
sub 30 min 5K sub 55min 10K
Check this article out. It's on the topic of confidence.
Life is not measured by the number of breaths we take, but by the number of moments that take our breath away...(unkown) • Go With The Flow • Thyroid Support Group
If it's causing you stress, just run for fun and don't worry about the times.
I see this as being two-fold:
One is experience. You get less nervous, or at least learn how to deal with those feelings, the more you experience them. So, really, it comes down to doing races.
The other aspect is in your last post. You want to do the best you can. Of course, we all do. But, I think that you're entirely too hard on yourself about it. Set a series of goals. You should have a primary goal, and then the goals above that one. If you don't make the secondary goal(s), you can be happy with the fact that your primary objective has been met.
Personally, I think you should find a routine. A routine that you do before training runs, that you can then do before races. That routine will help calm and focus you, and tell your body that you're now ready to run. Whether it's a word you repeat, or a series of stretches, or doing strides off the line. Anything works.
That and remembering that it's just a race, tomorrow is a new day, and not meeting goals does not equate to having someone dragging you out back and flogging you. Unless you like that.
I tend to get overstimulated and my brain likes to go a million miles per hour before a race.
Wally & Leela
It does not matter how slowly you go so long as you do not stop. --Confucius
My wife has always had a problem with stressing about the course & what is ahead of her too. Now, we just try to get a course map online (or where ever we can get one) and go drive the course the day before the race.
I've actually thought about doing that!