How to look older?

I'm 22, but people almost always assume I'm 13 or something. It's probably because I'm 5'3, rather slim and flat. Also, I have a small face.

I get treated like a child, and nobody takes me seriously during any social interactions. Even when I went to vote, people asked me if I'm old enough to vote, and then they began petting me. People always act shocked when I tell them my age. It worsens my social anxiety. Also, guys my age have no interest in me because they think I'm a kid.

Is there anything I can do to look my age? What can I wear to look "older"? Any makeup tips?

How to look older?
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