How To Over Come The Fear Of Stuttering Or Stammering?

hello dotor,im 28 years old and i have a kind of stuttering problem. when i talk with any one in phone or sometimes in direct, suddenly i get stuttering and i feel unable to communicate with dem, i cannot able to speak den for few seconds and minutes. i try to find the easy way to speak, instead of what i actually thought to speak. at same time my voice gets slow and my heart beats gets increased and i feel very tensed. i got this problem since my childhood and i have developed stage fear since childhood. how can i over come my problem