Shyness
Shyness is a feeling of insecurity and embarrassment or shame regarding oneself in the face of new social interactions, that consequently impedes an individual's ability to engage conversations or relate to others.
Shyness generates a state of discomfort rooted in the assumption of the possible negative outcomes to relationships with others. There can be accounts of "public shyness" as wells as "personal shyness"; the former concerning those who adapt to and take part in social life despite suffering it; the latter concerning those who have difficulty interacting. One accomplishes adapting to socialising and controls their discomfort with it whereas the other can't.
It is common for shyness to worsen if the cause of said reaction isn't addressed or if a "safe" distance isn't established in relation to the stimulant or agent, in this case relating to and socialising with others. Overcoming shyness is a slow process as it is inherently related to many different aspects of an individual's personality.