It's a very common topic I explore in sessions with clients; feeling good enough, productive enough, letting others down, not achieving what should have.  It's interesting establishing how individuals monitor and measure this.  Although I am a therapist I am no different, I experience these thoughts at times.  Am I a good enough parent, partner, son, brother, therapist.  How do we find the answer to the question/s, I realise sometimes we do, often we do not.  It's hard to measure, quantify particularly when the people we think deem us not to be good enough often don't tell us for a myriad of reasons.  Self-doubt and feelings of inferiority can massively impact our existence and life experiences, but with time and practise we can create positive and kind narratives which create a healthier inward dialogue.  It's not uncommon this can take months and years, but with support it can be life changing.