Hello vamhh and welcome to WebmasterWorld forums. A few questions back - Why do you think it is "Sandboxed"? Do you have messages in GWT? It is very normal for new sites to get good SE position that goes away after the quick "honeymoon" is over. Alexa ranking is not an indicator of anything that matters.
You mention that it has no advertising, do you sell any products via the blog or is it strictly your personal interests? If it is strictly personal, just try to inform, share and enjoy it and don't worry about how and where you are ranking. Post when you have something to share.
Should you improve? Always. There is a lot to learn about managing your site and keeping your content online and the more you learn, the more you find to learn and share.
This is what you like to see with a new site: steady growth. Natural, multiplying, over the next few months. A solid start with a good path to longevity and eventual authority. Keep doing what you are doing. Don't be seduced by short cuts as those will hurt more in the end.