10 weeks in 1 bag

How on earth I am supposed to pack for 10 weeks in 1 bag? I know that I have laundry and I can mix and match outfits, but let's be honest I don't want to wear only 5 outfits for the whole time I am there! I just attempted to make a packing list and pull out some things I want to wear while I am there. There is NO WAY that it will all fit in one bag that weighs under 50 pounds. Then what do I do when I want to bring stuff home? How am I supposed to manage this? I have no idea! There has to be a way to survive this crazy inability to pack my summer into a single suitcase. I should be sleeping right now, but I feel like I am being pressured to get everything done and everything figured out. The clock is ticking and getting closer and closer. I need more time and some kind of miracle!