Do you have a friend you can ask? Maybe another instructor in your gym? If nothing external has changed, it could be hormones making you smell different, but it could also be hormones making you perceive smells differently. Just a guess!

If you eat much meat or dairy products you might want to try cutting them out - even if they never gave you BO in the past. Maybe try the crystal deodorant too - that's the only thing that doesn't make me smell worse.