Stop researching keywords and complicating SEO. Keyword research tools don't show real volume and all available keywords anyway.
Instead:
Quickly write a post and wait till it is indexed by Google.
Open Google Search Console and check keywords associated with the page.
Rewrite the post to incorporate the real keywords and if possible to satisfy the real intent behind the keywords. Don't forget to update the published date.
Submit the updated post to Google for indexing.
I have never seen that the traffic doesn't grow faster.
Repeat that periodically. You don't need more content, you need to review and update your current content more.
Bonus: no need to spend thousands of dollars on expensive tools and agencies.