Oh my goodness another anaphylaxis sufferer! I went through that hell for almost an entire year, also never had true food allergies .
Ironically I also had chronic constipation problems too. I couldnt have a bm without an enema for 9 months.
Looking at your diet, you're eating a lot of foods that are high in histamine. When you're dealing with anaphylaxis, even while on antihistamines, you'll want to keep your histamine levels as low as possible. Excess histamine will also contribute to chronic constipation too.
By following a Low Histamine Diet I was able to cure my anaphylactic tendencies without antihistamines. I am also regular again. Colostrum and raw milk also had a big part in getting things moving again.
Check out the failsafe diet. It was a life saver for me truly!