Hello, I have been a member of forum since 7-8 months now and was ranked a Junior Member a few days back but recently i coudn't login due to bad health for quite some time and now finally when I was back and healthy and logged in, it showed my rank to be a Newbie. Can anybody elaborate what actually happened? 
Hey it seems you had no prior merits before September announcement, which clearly states if your account had no merits you would be demoted to newbie rank. Here you can not only read the details but even participate to learn more https://bitcointalk.org/index.php?topic=5030366.0. The only way you can move up is to gain merits, simply add quality posts, actively participate in discussions and lastly do not beg for merits.