Use confident, firm and diligient tones

I went through two phone interviews today. The first phone interview was scheduled a couple days ago. I did not feel good about my speech this morning when I was doing the morning exercise. My newly acquainted stutter friend called me in the morning. I told him about my interview. I stuttered a lot this morning when I talked to him. I told him that if I disclosed my stuttering in advance, I would stutter more. He told me that he is just the opposite.
In general, if a PWS disclose his stutter, he/she will stop hiding the problem. This will take off a lot of stress. Usually the PWS will speak better. I think it also depends the situation. If it is a interview, it might different. If I disclose my stutter before hand, I admitted that I have a weakness. It is not a disability per se. It is just a disadvantage. In current bussiness, commercial environment, communication seems to be the key for success. I have disadvantage in this key point. What should I do?
I am gaining courage and hope from many examples. There are so many famous people who stutter. Their professions are widely spread in every field. Successful businessmen, movie stars, broadcasting, salesmen, politics, scientists etc. They can do it. Why couldn't I?
The second phone call was unexpected. It was a call from a small company in NJ. The person calling me is the CEO of the small company. I taked in a slow pace and firm tone in the second phone call. We talked about 3 to five minutes. He invited me for a interview for next week. I am not sure if I am going for the interview. I feel that if I speak in the way I trained myself in the morning exercise, I will be ok for the interview. I will use the firm and confident tone in next mondays interview. I will perform the way I could.