It's an individual thing, but I personally find salad quite hard to digest. With the tomato, peppers and chilli seasoning you've got quite a bit of nightshades going on there. I'm allergic to avocado - could you have a bit of sensitivity to it?
Maybe something a bit blander would be wise - some plain chicken, cooked vegetables. Perhaps some macadamia nuts, and some coconut (whole not oil). Or a well-cooked omelette. (undercooked yolks disagree with some pple too)