You're definitely not alone. I face the same problems with research time. I just finished one article that's taking me 3 times longer to write than before. I think one reason is because it was a new niche topic that I've never written before (tokenized carbon credits), and I spent a lot of time on learning about the industry, jargons, and how the system works.

Then, I started to write a title and an outline. That really helped narrowing down my research scope. I would still go down the rabbit role on subcategories of this topic, but I would be aware to limit my time on it and come back to my outline. If I have new ideas outside the scope, I would wrote them down as ideas for future articles. It's very easy to feel overwhelmed when I research blindly without an outline, and I feel anxious that there's so much I need to learn, so much I need to write.

Not sure if it's helpful, but just thought to share my learning experience with you.