Self-confidence and psychiatrist, gain self-confidence, develop self-confidence
If you feel really overwhelmed by a feeling of inferiority that you associate with a particular hang-up, go and seek medical advice.
If you're convinced that your happiness would be complete without those under-eye bags, see a specialist (dermatologist or beauty therapist). A good specialist knows the difference between a tangible little anomaly that can be corrected and a bigger problem that requires behavioural therapy.
If your hang-up isn't about your appearance but it is holding you back significantly, speak to a therapist.