Severe depression. To face this problem?

As iam suffering from depression from nearly 16 months .iam unable to control the my mind. I have paining the mind nearly for 4 months .As iam unable to bare the mind pain .The most effect paining in the small brain .As iam unable to diagnose the what's happening in my mind .Iam concluding that my mind is damaging day by day.As iam unable to control my mind many recurrent thougts completed situations are automatically remembered by my mind .Due to this iam unable to concentrate for a seconds .Iam forgetting everything such as myself Including my good name,my parents,my home ways and Iam unable to speak properly,can't remember speaking words properly , unable to know what iam doing, which kinds of words iam speaking ,where iam and etc.Due to depression iam unable to control my thoughts and thinking , iam overthing for each topic  , Iam nearly over thinks for 1 year .confusion is become more and more .i didn't consulted a psychriatist never before .Please help me to face this problem