Hi, Sorry for the late response.
Lets forget rest of the code for a while. I have found out that adding sheets in excel in general is causing problems. If I try to add sheets one by one, after 10 or 15 sheets it starts causing slowness. i was previously working with Excel 2010 but never had such issue. This is only with the 2013 version. What can bet the cause of the issue and how do I resolve it?

Thanks,
Vibhor