Hi friend , with the brief information provided, you seem to be holding back your fear or guilt feelings that is troubling you constantly from within. Mental health practitioners will help you to regain your self confidence and handle your problems .

Hello miss/mrs. 1. Starting with your 1st Issue of being silent &      introvert can be part of your personality      ( mostly people avoid to talk much when          there is a sense of low confidence, fear of       criticism/ scrutiny, not much aware of things        around, feeling of inadequacy towards      oneself, fear of facing social settings etc ). Personality is a heterogeneous mixture of your genetic trait , Nurturing , Intelligent & emotional quotient . 2. Secondly, loss of interest in activities which     was previously present for same activities.     This can be due to fixed stereotyped pattern              of your life which lacks recreational activities,     mild exercise, your hobbies, good sleep &      quality  of time with family. OR    Mild depression can start with decrease in    interest. 3. Both the above complains requires particular     time duration to diagnose .

Need to be evaluated