What should I do I like a girl I met online, but she's now dating someone else. I'm torn between confessing my feelings or staying silent.

So I recently meet a girl online. It's been more than a month since we meet and we become really good in short time but the thing is I started to fall for her But I didn't confess to her because she have past trauma with her ex and I didn't want to mess things for her by confessing my feelings so I just help her to move on with hiding my feelings for her but recently she said she moved on and start dating a older guy. I really wanted to tell her about my feelings but now it's too late. What should I do now if I confess her right now and she don't accept it our friendship will not be the same probably we even stop being friends but if I don't confess and stay with her as a friend it hard for me to see her becoming someone else girl. Should I confess and erase her or should I stay as friend with the person I love?