Congrats, you've proceeded to the area of relationships least covered on this site - what to do when you actually GET the girl.
The simple answer is all of the things you did to get her
2 months is just enough time to let your guard down and get comfortable because you think she's already in the bag. What most men fail to grasp is that the first 3 months are the most important. Not only do they set the frame of how you relate to each other, but in this time she is also observing and tearing apart your every move during this time to determine if you have what it takes to meet her needs.
What she is searching for is congruence, and if you were acting the part throughout the seduction, you will fail as soon as the disguise is revealed.
Of course maybe she is just depressed for another reason? Does she laugh at anyone else's jokes? Do you spend a lot of time with her? A lot of variables can affect the situation.
