Have you looked into MCAS? Please do, as this sounds similar to what you are experiencing.
Hello~Have you been checked for "Candida"? This is a type of yeast infection that starts in the gut but it can cause all kinds of issues, including the ones you are having. There are several good books regarding it, the one I like I like is by Dr Crook called "The Yeast Connection" It explains what it is, how is effects us, what causes it and the diet to follow. The reason I am thinking your condition is caused by "Candida" is due to the fact that smells cause you such discomfort, Candida definitely can cause those issues.
I would suggest you start with a yeast free, sugar free diet, as these items cause Candida to grow, thus, causing the symptoms. Also, try to avoid high carbs as they, too, will contribute to the issue if it is Candida.
There is a supplement called "Caprystatin" that is great for helping Candida patients, it can be obtained from most health food stores or on-line thru my favorite source called I-Herb, they carry so many brands of supplements at really good prices.
I hope you feel better soon.