Can an introvert change their personality or is it biological?

Im still wondering whether an introvert like myself can really change their most inner personality…

I know this is probably something i can debate with myself but i would really like a second opinion by all of you out there.. lets think together.
They say two heads are better than one lol right?.
Anyhow, since my childhood me and my sis was always quiet and shy children. From what i learned during psychology class ,every personality starts from the up bringing of a child and it affects the persons personality on a later stage. So as children our parents didnt really allow us to blend with other children or to go out as we please, due to fearfulness of bad influences and getting hurt. This i have a great understanding makes children rely on other people rather than themselves. It reay disallows you to come out of your comfort zone and it gets even harder when you older. So being an introvert person, means that your shy, not out going do not initiate things unless its told for you to do so. You can be dependent, and pretty much like your own company. This becomes a problem even for me ,when considering a career or amy public event where confidence is required. For me it wasn’t so bad my first job, which was marketing in public and it made me understand people and also be talkative in such areas where i lack. But no matter what, when you get back home or are just in your little bubble you find out that its not naturally the way you are. Most of what you present is forced out of you and all you really want to do is be yourself. Be quiet ,enjoy your comfort space, hide away from the world and do your own little sensible anything. Im a independent one, or im working on it most of the time lol. So do share ,what you think about this topic, can introverts personally change or is it biologically so ,no matter what?