Salaam - What should I do about this situation?

Assalamu alaikum, I’m almost 18 and I’m unsure whether I should mention my age or not. I recently found out a young man has a crush on me. Having a crush isn’t inherently wrong, but I’ve only ever seen him from a distance and never spoken to him. He learned my name and who I am through my cousins, who are his friends. A couple of my male cousins have been telling him about me. After that, he kept messaging my cousins saying how attractive he thinks I am and that he wants to marry me, and he’s been asking them for more information about me. I only discovered this because my female cousin saw the message thread - one of the boys is her brother - and she felt she had to tell me even though she initially didn’t want to. I feel really uncomfortable and upset that there were so many messages about me and I had no idea. He’s even saved or sent my profile picture among his friends; I stopped using a display photo two months ago, so that helped somewhat. Still, it feels wrong that images or comments about me are being shared in guys’ chat threads. This goes beyond a harmless crush for me, and I want to take action. I’m debating whether I should tell my mother or another trusted guardian. What should I do? Should I involve my parents, ask the cousins to stop sharing information, or take other steps to protect my privacy and honor? Any advice on how to handle this in a way that’s respectful of our values but also keeps me safe would be appreciated.