Legal Expenses to Fight False TM Infringement

I'm an author of contemporary romance, published for ten years. Recently, another author accused me of infringing upon her trademark.

I published a series of books called Career Soldier beginning in February 2017. In September of that year, the claimant published a non-fiction series that she also called Career Soldier. In 2020, she filed to trademark that phrase for non-fiction use.

The claimant has caused Amazon to remove my series from sale on their site and demanded a settlement payment. I am looking for an attorney to represent me in clearing up this situation, which may end up in costly litigation.

I appreciate the support and encouragement of my publishing community, readers, and friends. Thank you so much!