I am in France on a year abroad too. I'm doing Erasmus work placements not study- but yes, I am finding it very demanding too.
I don't think I fully thought things through before I went. I thought "Oh wow, here I am, I'm going to have this awesome year in Paris which is a beautiful city, and I'll have a cool job here and I'll make loads of French friends and I will become fluent and I'll be fine". A lot of my friends were the same, also quite blase about it.
The reality has been quite different, of course. I have had to make an extra effort to make friends because I'm not at university, and when I've found French people my age, I've found it difficult to talk to them because of the difference in culture. I assumed that because France is in Western Europe, there'd be at least SOME common ground, but my friends and I didn't grow up watching the same TV shows, for example, and didn't go through the same education system. And these little things meant that I couldn't join in very much at first in groups entirely made up of French people. Add to this the fact that my first placement wasn't quite what I thought it would be, and that I was turned down from other jobs because my French wasn't good enough, and you have a few things that made me wish I'd stayed at home.
And yet, despite all the crap I have been through, living in the crappy part of Paris where I live, dealing with ****ty people and not managing to make myself understood, I think this year has been unforgettable because I have learned that there's a world outside the uni bubble, and that I'm able to cope. Being knocked down has given me a lot more confidence, and I think you need to see this year in that way, rather than getting your hopes up too high. People have amazing times on their year abroad, but not for the reasons you might think.
Incidentally, I also think that French people have something to do with it. My Dutch teacher at uni once said "The difference between German and French people is that when you go to Germany speaking German, the Germans are so happy to have you because you have made the effort to learn their language that they automatically welcome you. But the French expect YOU to be the one who is happy to be in France, and once you show that enthusiasm, they let you in." So I always smile and say bonjour and usually that works!