I've had this issue off and on for over 5 years now. I can't say for sure that what causes your smelling smoke, but I can pass on what I know about mine.
Mine is caused by foods that have dicalcium phosphate in it. There are other names for dicalcium phosphate that you'd have to look for too, they are:
-dibasic calcium phosphate
-calcium monohydrogen phosphate
I've also found the related compounds also cause the smoke smelling, they are:
These are in a lot of things. Wheat tortillas, cereal, soy milk, almond milk, salad dressings...a lot. I found a little, like maybe having just one item with dicalcium phosphate in it doesn't seem to cause the smoke smell. It's when I'm eating this stuff every day. So I figure it's building up in my body. So, when I start smelling smoke, I look at ingredients of what I've been eating, stop eating it whatever has dicalcium phosphate, and a few days later, the smoke smell will go away. I'm assuming it's just taking a few days to get out of my system.
Oh, its also in otc medicine. I think it's a filler, so look for it in supplements or vitamins too. Remember, its not in every brand of the things I listed, but it's also in so much more food items than I listed!
I hope it's as simple for you as it was for me. You're too young to be having to try to figure out why the smoke smell when there's no smoke around.
Good Luck! And if you find this helps you, please post it back here and on other boards, to have this be the cause means it's a very cheap fix. I've read about a lot of people spending a great amount of money on testing.