Welcome to our family I have heard that Beta Blockers can affect the sense of smell and this may have more to do with your nausea at the smell of chemicals than your possible AI issues. What type of steroids are you taking for your Asthma? Is it Prednisone? Please be careful when taking steroids for symptoms other than what they were prescribed for. If the steroids do help you, perhaps you can talk to you doctor about prescribing the right kind of steroids for you suspected AI issue. Prednisone, for AI diseases, can be a Godsend. But, there are many, many precautions that you must follow when using them. One of the precautions are the fact that it is a drug that you must taper off of and should be taken for specific course of time. So, please, please contact your doctor so that you can get the correct prescribed steroidal drug.
You are not alone in your conclusion that you've suffered from symptoms for years prior to being diagnosed. I think that many of us have come to that same conclusion. Also, it is not at all uncommon for our lab work to be negative and for us to still suffer from the symptoms of an auto-immune disease. That is one of the reasons why these disease are so difficult to diagnose. Many here have suggested and/or employ the use of a journal to list your symptoms and describe when they occur. This journal can be very helpful when meeting with your doctor so that you can make informed decisions together about what is happening to you and what course of treatment you will take.
In the meantime, you may vent here as much as you like. We are here to help you in any way that we can. Again..welcome!!
Peace and Blessings
Look For The Good and Praise It!