I thought of another great technique, which is not "easy" but if you can apply, it's the best thing ever.
I consider it "masculine" but someone else may have their own take on it:
"Confidence" is bullshit. "Confidence" is simply situational competence.
Nobody can ever overcome anxiety.
But instead, understand that anxiety is evolution's way of telling you that you need to act.
When you feel it in your head, stomach and chest, consciously put your attention on your feet, legs and pelvis.
You will find you get a mad rush of energy and can barely stand still, and you will break into a smile without meaning to.
From being "closed" you become extremely "loose", from being "frozen" you become extremely "quick on your feet", from being "flustered" you become extremely "centred".
In this way, with practice, the more "anxiety" you feel momentarily, the more "relaxed" you immediately become outwardly, and the more "energetic" you feel inside, in fact, to a much greater degree than before you felt that anxiety/energy rush.
Not so easy but anyone can do it with studying and practice (countless vids on YouTube), and when you do, it's amazing.