Being tired makes me more sensitive to sounds and more irritable. Menstruating and ovulating makes me very aggressive, irritable, forgetful and emotional. I have celiac disease so I've been avoiding wheat for several years now, so that has helped a great deal. Eye fatigue, from computers and/or flourescent lighting, also seems to increase my sensitivity to sounds and my irritation.
If I don't get enough sleep (8 to 9 hours a night) and can't have a quiet lull in the late afternoon as well, I not only get irritable but I also eat more and crave fatty carbs (roll on, potato chips and cheese dip!).
As I've gotten older, I've been less able to cope with fulltime jobs and can now only really manage part-time work. I need too much downtime and recovery time to work fulltime. I suppose if I were single, I could probably hack it again, as I did for many years. Now, I already know I wouldn't be able to handle the constant stimulation of a day job and then coming home and needing to deal with another person's needs and expectations. Meditation helps, as does playing Solitaire on the computer while listening to music over the headphones. Fortunately, my husband likes to watch long, quiet golf tournaments on TV, so there is plenty of time for me to do this!