Distressed when try to speak

Hi, I feel distressed and under pressure , when I try to speak and express myself in an environment, in which I feel inconvenient.

Except for when being with my friends, parents or person with whom i feel warmth and secure, I cant easily speak. I am silent and I feel that I put pressure on my self and I will explode. For exaple, in the team with my collegues, with whom I dont have a close relationship, I cant speak easily and answer with yes or no. I don’t know what to do in order to get out of this situation.