4 links have been added on this idea.
  1. Here’s another drug that can boost your confidence by making you less indecisive.
    https://geneticliteracyproject.org/2017/06/07/plagued-indecision-drug-may-boost-confidence-help-treat-schizophrenia-ocd/

  2. According to this news story, a beta blocker drug used for heart conditions can also treat anxiety, giving you a huge dose of confidence.
    https://www.statnews.com/2017/10/25/anxiety-performance-propranolol/