Low self esteem, always questioning my abilities and very very careful of what ppl say or think about me?

Try psychotherapy: You should see a psychotherapist for a diagnosis, treatment plan, therapy, and if necessary a referral to a psychiatrist.Best wishes.

Psychiatric eval: Although some of this may sound like classic elements of a personality disorder, diagnosis should only be established through a psychiatric evaluation. See your dr, for reassurance and/or treatment if indicated. Psychotherapy almost certainly will help. Best wishes.