I've been going for 2 years now and have always gone into the studio barefooted. Maybe this is just my personal preference but I didn't really mind the smell -- probably got used to it after a while. Needless to say, I never developed any fungal infection or anything of the sort for stepping around the sweaty studio LOL. I normally would avoid the big puddles of sweat in some areas though. Maybe you can also ask if you can use indoor slippers to avoid stepping onto the carpet directly.

It's really great that you can complete all poses and stayed in the room. I'd say give it a few more classes and see if you feel any positive effect.

I wear my flip flops to the door and then when in the hot room I just avoid the puddles of sweat (usually I wait until they have mopped up after the previous class then I don't have to worry about, but sometimes I need to get my spot!) I have had the unfortunate experience of having a fungal infection and having half my toenail fall off, but I didn't get it from the studio.

You will get used to the smell. I wash my hair after every class but I don't practice every day. I don't wash my hair on the days that I don't practice. When I did a 30 day challenge I just used a lot of deep conditioner, a good leave in and more oils on my hair as well to make up for all the washing.