False accusation about me spreading socially (16) — how to handle it?

Location: Germany
Hi, I’m 16 and dealing with a false accusation (sexual assault) that’s spreading among people I know.

It’s not a legal situation, but socially it’s getting worse — people are messaging me calling me disgusting, and others are starting to believe it. The person who started it doesn’t have any evidence because i never did something to her or even said disgusting stuff to her. I do think she just faked messages. We we’re in a realtionship but when i broke up with her she started dming people who i know and told them that i assaulted her.

I’m trying not to react emotionally or make things worse. I haven’t confronted the person who started it.

I’m doing like really really bad mentally, i haven’t eaten for days, i’ve been crying a lot, i even start trembling when someone texts me about it, my mom is also worried about me, she’s saying i don’t look as usual but i don’t want to tell her about anything and i’m even thinking of doing something bad to myself.

I’d appeciate any advice.