Whenever I have started a new job, I always go through a period where the excitement of it all causes me to sleep less. If the job ends up being routine, I will settle down after a while but if it ends up being a stressfull job, my sleep problems continue on and off.

I simply learned I usually can still function on less sleep. I go into the job with the attitude that I can't let the lack of sleep interfere with my life and cope with the aftermath (double checking my work, etc) as it comes.

I just look at it as there are some things that we can't change and try to enjoy the extra time I have because I sleep less.

Sorry you are struggling with this. Less sleep does effect your concentration but you can still muddle through.