I have so much voices in my head about something that i failed to achieve and all of sudden I reply to myself in a loud tone. So, i would like to ask what is the reason behind this? Is this a serious kind of mental issue or normal? Is there any remedy to stop this?
Astrologer_41712 
Which mahadasha you are running in?
Where is moon? Does saturn/ketu/rahu with moon ?
Try to read good books,eat healthy,sleep for 7-8hours. Practice yoga and meditation.