Practising public speaking is a useful way of connecting with the confident development of your speaking skills.
Blushing is an indication of your anxiety, but it does not define you as an “idiot” or a bad person. Your reaction to the blushing is making it worse. Being preoccupied with “I’ve got something to hide” will trigger more anxiety.
Aim to keep your focus on the speaking skills (you are good at what you do!), develop techniques that can lower your anxiety (breathing), and then focus outwards with confidence (externally, and away from your internal symptoms). Your audience will accept you, when you can accept you.
http://www.clinicalhypnotherapy-cardiff ... echniques/