baaaahahahaa sorry but this is soooo hilarious to me!
your not alone, shes not a loony beatch

, we all handle the stress (yes, diets are stressful for us) of dieting different, and there is not a flat universal way to respond to each of her mood swings, sorry buddy lol.
I can tell you what would help if it was me, and that may help you.
If she has an "episode" (<-this is what we call mood swings in my house lol) maintain your manly calmness as her rock of sanity and say your sorry shes feeling off (i wouldnt say irritable or pissy or anything cuz that may upset her more if thats not how she thinks she feels ) and you will give her space and you will be here for her when she wants you, than give her the space. She maybe in a sparring mood (lol) but dont get drawn in...a simple love you babe, I'll be over there when you need me...than walk away and dont pay mind to what shes saying, she doesnt mean the vomit she's dumping on you, its just her frustration/irritation coming out and your her rock/safe place so unfortunately for you she feels safest letting go around you. ....its a sign she trusts you and feels safe with you ~ you should feel great about that! lmao
"Researchers from Oxford University found that three weeks of calorie restriction depleted tryptophan levels in both sexes, but especially in women. Diets really do make women grumpier, stress, poor diet and a lack of exercise (and even a lack of sunlight) are all thought to deplete serotonin. Female-brains-wired-increased-anxiety-depression. This may explain why women tend to be greater chocoholics than men, especially before a period when oestrogen is low, or during perimenopause. They are self-medicating with carbohydrates to raise their serotonin to stave off the grumps."
scientists from the Karolinksa Institute in Sweden