There is nothing wrong with your introversion. Zero. In fact, people that listen more and talk less are known to be far more intelligent then the blabbermouths.

If you want to practice having the self confidence you desire as seen in extroverts by default. Take a tape recorder or use the recorder on your smart phone to take audio notes.

Anytime you feel like spewing out what is in your mind, do that as practice. You should trust yourself implicitly and if you are alone, trust the recorder as an extension of you.

Then get it transcribed or written down.

The other thing to realize, when you do speak. Your words pack 1000x the punch of an extrovert.

Remember that you words matter a lot more, and have a strong impact.

That being said, what I have found in my travels is as an ENFP-T who finds Introverts "very intellectually stimulating and sexy as hell" ...

I have noticed in my life, when the introvert becomes so comfortable that she becomes an extrovert, I then become the introvert.

It is a fascinating dance.

So don't feel bad about your gift, embrace it.

If you wish to improve your communication skills, then work on building confidence and safety of your being.

Self defense courses, exercise to improve body positivity, take public speaking courses etc ...

Only surround yourself with good people with good intent too ...

Be well!