Akash,
Most Type 1 diabetics go through a "honeymoon phase" where they still have some beta cells in the pancreas, but slowly the remaining beta cells are destroyed by the immune system. As the cells are destroyed, you produce less natural insulin so you must inject more insulin. That is probably what is going on here.
Diabetes sometimes gives you periods where your dosages are fairly predictable and work pretty well. But then things change, sometimes suddenly, sometimes gradually. I know how majorly it sucks when you've gotten the hang of everything and then you need to relearn everything - it happens to me pretty regularly - but the best thing you can do is adjust and move on.