If you are noticing a stagnation in your blog engagement and traffic, maybe it is best to take a step back and start looking from another angle. Go back to your roots and think back to the reason why you started it in the first place. Was it to make money? Have a creative outlet? Connect with like individuals?
Obviously,
your purpose back then could be different from your purpose now. That is completely okay. However, it is important to address whether or not you are fulfilling that purpose. It might be hard to believe, but readers can sense if there is passion written behind the words of a blog post. If you are simply writing hollowly with no real goal, it can be quite obvious. A reader is much more likely to stay and engage if they can sense your passion and excitement. This can only come across if you have reached self-realization of your own blog intentions.