Dealing with Unreasonable Client Edits: Seeking Advice from Writers

How do you handle unnecessary edits from a client? Writer friends, I love the business this client is in. We cover anything and everything about ADHD and this is something I am truly passionate about. But that love and passion is now fading away because the edits from this client (he's the marketing director, not the editor, but he's the one working on the edits with me. Why? I don't know.) are very unreasonable and frankly, unnecessary. I know edits. I'm not perfect so some things may slip. My editor may have better ways of framing an idea than the sentence I wrote. There's a tone and writing style to keep in mind. I get all these. But the edits for this client: They're second-guessing lots of my sentences, as if there's no hyperlink where I got the information from. They're questioning the way I write, like I have to justify why this sentence or this word should be used or written this way. They're asking questions like, "is this a thing" so now I have to go back to my sources and send them the links to those. Sometimes, I have to explain in-depth how it's a thing. Like I said, I get edits. I've dealt with tough editors and I learned from them. This time, however, I am not learning anything. I'm just spending more time when editing because I have to justify every sentence like he doen't trust that I did my due diligence of researching and fact-checking, especially that this is a medical niche. Question: What should I do? Because right now, I can't afford to lose this client. Unless I get a $1,000 new client. Help! tysm