Yes, you can achieve fluency. And a year is an attainable goal. For me, there were no jaw exercises. Breathing is obviously a key component in speech, so I was taught to use my breath properly. No exercises there, per se. Just a focus on always starting with enough air and starting my air before starting my voice. My speech therapist basically taught me to speak from the ground up. Developing speech fresh, as opposed to trying to transition my existing disfluency into fluency. As to 25 years later? Still fluent. Not silver tongued. Haven't practiced in years. It became second nature after a while. After achieving fluency, the anticipation of stuttering fades over time.