Most speech therapists don't know how to do good stuttering therapy. Most speech therapists don't even understand the real issues of stuttering, let alone how to treat it. And ok including maybe SLPs who claim to be stuttering therapists. If your therapist is giving your breathing or fluency shaping exercises and you don't feel it's good, I would seek a new therapist. Your instincts here sound completely correct. I wouldn't give her any more time or money. You should be able to understand the reason behind everything you're doing and it should make sense to you.