How do I become quieter and stop oversharing?

I’m really tired of feeling like I’m responsible for everyone and everything. I want to learn how to talk less, stop oversharing so much, and be more comfortable just keeping things to myself.

I’d like to be quieter and draw less attention to myself without completely isolating myself. The problem is that when I do get quiet, people immediately assume I’m upset, being distant, or doing it for attention, which makes me feel like I have to explain myself.

For people who used to talk or overshare a lot, how did you learn to pause, keep certain things private, and become more comfortable with silence? I’m looking for actual habits I can practice.