I had this problem in high school (and still deal with it now).
What I found helps is:
a)clean up your diet! No sugar, fast food etc. I am on a gluten and dairy free diet too but that is because I was always getting an upset stomach
b) drink A LOT of water every day. You need to flush out any toxins
c) I take digestive enzymes before I eat a meal, I take olive leaf extract in the afternoon and I take probiotics after my dinner. I am trying to help my gut flora re-balance. Of course, consult your doctor first in case these remedies may not agree with you as an individual.
d) exercise! I always ensure I work up a good sweat exercises each day before I have to go to work. Plus it keeps you super fit :)
e) try not to stress - this always makes me more likely to smell
My Mum can never smell anything either, but I know I do smell at times because I have had people come up and comment to me about it. It still helps to talk to her about it.
Stay strong, remember this problem does not make you a bad person. It is just an unfortunate circumstance. It will make you stronger.