It's possible that 1,500kcal is just a tiny bit low, especially when your body is working hard to 'repair' some of the damage caused from your long-term allergic reactions. Maybe your fatigue is actually from the caloric restriction?
I've also noticed a pretty impressive improvement in energy, digestion, and overall focus when I added naturally fermented foods to my diet. Yogurt is out, obviously; but homemade sauerkraut is super cheap/easy to make, and kombucha is another easy one to add, if you're interested. Sprouted foods (ie. lentils, beans, some seeds, etc.) are also a fun way to 'change' your food so it's less inflammatory. It may be something to look at, anyway.
For myself, I also notice a big difference in how I feel when I eat farmed protein (ie. supermarket eggs, milk, meat, fish) vs finding a different supplier (organic dairy, grass fed meat, wild fish, local/no drug eggs). The first category can make me sick as a dog - but not the second. Same for wheat/bread - the store bought stuff gives me wicked heartburn/diarrhea, but whole flour (ie. fresh ground, not 'whole wheat') in a proper sourdough bread (fermentation is an incredible tool
) is awesome - it also tastes better, and is more satisfying to boot!