Have you gained weight? If you're overweight, the fat pad at the mound and base of the penis can hide part of it which would make you appear smaller.
Are you not getting fully erect which will also make it smaller? Many things (physical and psychological) can cause a guy not to get fully erect. You mentioned you had depression, are you on any AD meds for it? There are a lot of medical problems that can cause it, something you might not be aware you have (high/low blood pressure, circulation problems, diabetes, low testosterone level, etc.) and also psychological issues can cause it. If you're insecure about your size, insecure about the relationship you're in due to being hurt in the past, insecure about your ability to be a good lover, they can cause erection issues.
Have you talked to a doctor about it?
In your first post you said <<i love a girl and when i was with her in bed, i felt afraid of that and i didnt continued with her. when i her abt it , she was very uncomfortable and now almost left the relationship.>> Was it your penis size that made her almost leave the relationship or your insecurities?
Were the two of you being intimate and you stopped it? That would make me think twice about the relationship.
I'll be honest, the size of a man's penis wouldn't be a deal-breaker for me, but him having insecurities about his size would be a deal-breaker. A penis is not what makes a man a good lover, it's knowing what the woman wants and needs, it's knowing how to pleasure her, willing to pleasure her, being enthusiastic about sex is what makes a good lover. I feel the same holds true for a women. A woman who is secure with her body, isn't afraid or shy about getting naked with her man, doesn't have insecurities about her body, knows how to pleasure her man and is enthusiastic in the sack, that's a woman who's a good lover.
Insecurities don't belong in the bedroom.
Love 
