Allergy testing has been suggested. Lioness mentioned enviromental testing for allergerns like mold, dust, pollen, cats and more. That is a simple 30 minute prick test on the back and for those types of allergies shots can help treat it.
I've had hayfever all my life and this test can even diagnose what type of grasses one is allergic to.
Your lungs may be inflamed because of allegens.
My biggest misery was inside my skin. Turns out I had 2 issues going on- chemical/natural element allergies and also diet- processed sugar feeding my internal yeast. Mind you I had no visible yeast issues.
My internal inflamation was raised by exposurer to all the hidden chemicals and elements we contact: preseratives in topicals like lotions, dish soap, grooming products and metals and acrylics, and blended fabrics like elastic, poly/cotton and elements in rubber and so many more. The test for this is the 5 Day Extended Patch Test, Google what this is about. Many, not all, dermatologists are licensed for this test, most allergists are. You may not even have external skin issues, your inflamation was be inside you body. Look up True Test Kit for this 5 Day Extended Patch Test. It is a common brand and the one I had. I was tested for about 80 elements.
Like you I've always known fragrance, good smeling or bad smelling affected me. I get a headache 1/2 a mile away from a diesel vehicle ahead of me in traffic, I know it's up ahead, before I see it and make sure my car airconditioning outside air entrance is closed off. I can't go into a store that sells tires because I get a spliting headache within a 30 seconds. Just the odor from the rubber, I get a rash from rubber contact. Rubber and elements of rubber are hidden in many of our contacts from floor mats, protective gloves, blended fibers like elastic and hundreds more. Most perfumes give me the same reaction, they make me sick, headache is the most immediate issue. I can't go into a home burning scented candles or a Christmas store full of cinnnamon fragrance. My 5 Day Test verified my allergy to cinnamon and to rubber. I had to give away my glorious lavender plants in my gardern because I got tired of holding my breath just walking by them, my reaction to their fragrance was that fast. Testing gave me the ability to avoid my allergens and learn where they are often hidden.
My second suggestion others have also mentioned. Diet. Give up processed sugar and limit natural sugar. Read The Yeast Connection Handbook by William Crooke, MD. The detox period is brutal, giving up carbs and sugars, after that the maintanence plan is doable. I learned I can eat gluten once or twice a day. It's the processed sugar which is yeasts favorite food. An overload of the yeast, which lives in our intestines, poisons us with their waste products by raising our histamine levels. Histamines raise inflamation. All is explained in the book, it's available on the internet. I've been off processed sugar now for at least 5 years, it's the best sacrifice I've ever made. It's not easy to give up sugar, it will take about 6 months of abstinance to begin to not crave it. Tell yourself when you want to grab for a sweet, "When will you learn, it's going to make you burn" then walk away. My desire to live pain free motivated me to make this sacrifice when my body was screaming at me for sugar.
Another testimonial from my sister who was in a brain fog for years, for example she'd find she walked blocks from her house and couldn't remember how that happened. For a 45 year old it wasn't dementia. Turns out she was allergic to MSG, which was more common in food years ago. She also did a detox diet and then maintance plan similar to the one I did and stuck to it for a year but now eats normally,though still off MSG and has had no issues for years. Personally I will never trust sugar again and know what chemical allergens to avoid for life.
You are desparate and will loose your mind if you don't figure out what is causing your health issues. I was at the point of suicide because I couldn't tolerate my internal pain any longer. I couldn't get more than a few hours sleep at night because of the burning and stinging inside my body. I'd get up every morning knowing the hell I would be facing again and again and again. I couldn't go on this way.
I became obsessed with the internet and spent hours every day on sites like this searching for answers. Be a warrior and fight for your health. I was. None of my recommendations will make your health worse, if you are as miserable as many of us have been you will give these suggestions a try. Please keep us posted on what you will try next.