I've got an ideopathic sleep disorder, so I've tried about everything. Been through 3 sleep studies. Done tons of personal research. Insomnia isn't typically my problem, but when I do have it, here's a few things that have worked for me that are outside the typical things that most everyone else would suggest (they'd suggest alterations to your sleep environment, relaxation techniques, glass of wine, warm milk, supplements, etc. ... I'll leave that to them unless none of them respond):
1) Better than counting sheep, and this one is free: This one is the simplest, works for a lot of insomniacs, just doesn't work every time for me. Count backward from 100 (not out loud). This tricks your mind into NOT dwelling on the things that keep you from falling asleep. The average person will fall asleep within 5 minutes IF their mind is not preoccupied. Whenever your mind starts to think about something other than counting backward, start the counting all over again. Since you are so tired, this might very well get you to sleep the first time, though you still may want to consider the below things for long term fixing your problem.
2) Brainwave entrainment using binaural beats: This usually works for me, but it may take you a little while to "train" the first few times. There are various CDs and entrainment programs out there, but I do recommend Dr. Jeffrey Thompson's Delta Sleep System, or his Brainwave Journey set (mainly for sleep you'd want Journey of the Body and Journey of the Mind, though Journey of the Heart would be good for dealing with some of the emotional/stressful issues that might be keeping you from sleep. You can google or do a search on Amazon.com for these. You want Delta or Theta brainwaves for sleep. I suspect you have too much Beta going on (Beta is a high alert state), or more Alpha (Alpha is alert, but relaxed). Theta is drowsy, light or dream state. Delta is deep sleep. You will need stereo headphones (this is a MUST for for binaural beats).
Despite Alpha usually being for awake, it IS needed to help go to sleep. While Alpha lessens through most of the brain when you go to sleep, it is supposed to INCREASE at the occipital part of the brain (that's the area at the back of your head) when your eyes close. It's something that cues the brain to relax. I'm an oddity in that my eyes-closed occipital Alpha does the opposite of what it should and increases. That may be what's happening with you.
3) Meditation: I always fall asleep before I can finish an entire session of Jon Kabat-Zinn's Body Scan Meditation CD. It's a guided meditation which has you simply noticing the body, what it's feeling, but not dwelling on any thoughts. This is basically shutting off your active mind, which is what #1 above is to do also (the counting backward). But I think this works much better for me. It's an excellent CD. I probably don't get the full benefit of the meditation because I always fall asleep, but I'm quite happy at my failure to get through a session because I need the sleep.
If you need some of the more typical sleep solutions, let me know. However, as tired as you are, I wouldn't suggest you take a relaxing bath because you might fall asleep in it. Save those for when you're not so sleep deprived.