Why cant I sleep ? I should be exhausted. The crazy turmoil of training for Ironman.

My training has ramped up, now that I am at 16 weeks until IM Couerd alene. It is Thursday and I have already completed 24 miles of running, 20 of biking and 3.5 of swimming. My head wont turn off. I can't stop thinking of how to properly set up my bike for hydration , what to put in my support bags. What clothes to wear for any sort of weather that MIGHT occur on JUNE 29th. WHAT IF THIS OR THAT...AugggH. It is 1 am, I was lying in bed starving , so I get up and eat a snack thinking this would get me to lights out. Nope. There is soooooo much to think about with Ironman. It excites me and terrifies me at the same time. Then, my mind wanders to what the heck am I doing? Is this the meaning of life? Why do I feel so compelled. I lay in bed nightly , surfing the internet for all my answers, like what are the best swim socks, and what do I do if I get my period on race day. The internet is a great place to get all sorts of opinion, on ANYTHING, I mean anything. Then I think of random other things like, what the next family vacation should be, got to get the yard cleaned up for spring and the deck sanded and stained, and oh what about this and what about that. And my next thought is if I cant sleep how the heck am I going to get up in 4.5 hours to train and go to work, and take care of the kids and .........please let me go to sleep.