It is high time now that you find out what motivates you the most to keep your blog going. Is it for money or just a past time activity. Do you want to be an accomplished author by gaining public recognition and become popular among your intended audience and then opt to launch the book you so eagerly wanted to be published. What motivates you is a matter of individual preference.
But motivation is a must to be successful at blogging as you need to keep going even in adverse times because it is not always a smooth ride in any field. The path to blogging success passes through some tough terrain and you must be ready for that. If you have the right and strong motivation to be successful at blogging then those tough terrains should not phase you out of the path and you will be successful for sure.