Easter weekend. Try on a normal workday.
>Why is it taking so long?
Your original file is large and your computer is slow... but, since you provide ZERO information, that is only a GUESS
A link with many ideas about computer setup http://forums.adobe.com/thread/436215?tstart=0
Work through all of the steps (ideas) listed at http://ppro.wikia.com/wiki/Troubleshooting
If your problem isn't fixed after you follow all of the steps, report back with the DETAILS asked for in the questions at the end of the troubleshooting link
I am no professional. Your help is appreciated. I will be working on this all day
This ARTICLE will give you some of the reasons that we ask questions. Those answers are basically our eyes, to look over your shoulder from our various locations, as we cannot sit beside you, while you edit.
I also agree that it is probably your system, your source footage (Assets), and/or you Sequence Preset. Then, the exact format/CODEC and specs. of the Export will make a big difference too.
Even with a monster machine, and really good Assets, the Export can make a world of difference with regards to time.