It does look completely unmanagable from this side of it - I remember that overwhelmed feeling very well. Didn't get much better for us in the second term, when we had eight coursework deadlines in six weeks. That took some very careful time management, so look ahead wherever possible and try to spot potential issues before they become actual problems. Overall, I found the Masters year full-on, for the full calender year. The sheer volume of reading and research was monsterous, and by my reckoning, I turned out the same volume of coursework in a term, as I'd done in my entire third undergrad year. It certainly was a different beast to my undergrad degree.
However, here I stand, with my Masters successfully completed. It does feel awful quite a lot of the time whilst you're in there, but I can assure you that the majority of people around you feel exactly the same (no matter how carefully they hide it!). It *is* do-able and this time next year you'll be so proud that you survived the experience!