Confidence follows finished reps
Confidence rarely appears before practice. It appears after you finish many small answers and realise that imperfect English is still understandable.
Use small prompts
Start with simple topics and short timers. A finished 30-second answer is more useful than ten minutes of thinking about the perfect sentence.
Track one improvement
Each day, improve only one thing: fewer fillers, clearer opening, better example or stronger ending. Small wins are easier to repeat.