I don’t like the go I am, How can I change

So I’m a really kind and sweet person. That’s fine. What I don’t like is aspects of my personality I’m too extra sometimes and too loud and it’s not like I wanna change for anyone else, it myself, I don’t feel like myself and I don’t know how to get to mself and I’m not even sure who myself is, help? Any advice ?? I feel

More like myself when I’m a little moody, not a mean moody but just not such a sunflower all the time, what I’m trying to say is I feel more like my when I’m slightly introverted but everyone who knows me doesn’t know me like that and I don’t want them to think I’m off with them

And of course when I wear certain clothes or outfits or hair styles I associate them with this person who I’m not comfortbale with so when I look in the mirror at my face and my clothes I don’t see me and I want to change that. Lucky for me highschool is nearly over and I can be easier when I’m in six form but that’s not till September