Hi and welcome!
I don't really have any answers to your problems, as my yorkie is only 4 months and I haven't had to deal w/ a lot quite yet. Maybe some other people can offer some suggestions.
As for the training classes, I'm sure they are used to dealing with dogs with issues, so I wouldn't let that deter you from taking her to classes. I plan on taking mine in another month or two.
By the way I'm Brandi and my baby is Hercules!