Music Licensing Question - fanfiction and derivative works

I publish illustrative scenarios prepared by my practice. All participants and conversations are fictional. The fictional posts are not posts by real users, accounts of client experiences, or reports of actual results.
Illustrative scenario prepared by my practice.
For informational purposes only. This is not legal advice. Laws vary by jurisdiction. Consult a qualified attorney for advice specific to your situation.
Hypothetical question

I'm dealing with a situation and need some guidance.

fanfiction and derivative works. I've been dealing with this for about 9 months now and the situation isn't improving.

This involves original creative work over the past 11 months. I do have documentation proving my ownership and timeline.

Am I overthinking this or is this a real legal issue worth pursuing?

Illustrative response

Following - dealing with similar IP issues.

Illustrative response

Thanks for sharing. Dealing with something similar myself.