If you saw yourself shrinking, then it means that there is a shortage of self-trust. You could also feel dull and not interesting person. Maybe someone humiliates you for a long time, therefore you started thinking about yourself on the worst way. The bad opinion about yourself brings depression and hard feelings which might lead one to suicide, therefore make sure you find the help from the others. On the other hand, the dream could indicate the old times when you were small as a child.