Congratulations, on your success so far.
Don’t beat yourself up. You are human, with human fears. Decide what you really want from your career, there will be options. Pick the path that will make you happiest.
Maybe you are not ready for the next stage just yet. It’s a transitional time in your life, follow the sign posts in your life, there will be many and follow your instincts. Stay positive, there will come a time when you are ready and a natural confidence will come.
All the best.