Hi there Ourobolus and welcome to A2K!
First of all.......I am going to asume that your girlfriend still loves you. It sounds like the past 2 years have been wonderful for you both. When you truely love someone, you don't just wake up one day and decide you are no longer in love.
I think you are just in a "rut."
Relationships go through phases. When you first meet..... the other persons attitude ~ body language ~ and all the long talks you have, are really special and unique. Your hearts are on fire & your passion is just as hot.
Then you start to evolve into a new level. One where you become more comfortable with each other. I think this is more like the "settling" in stage.
It's probably also the stage where you "cement" your foundation. Your feelings for each other deepen. The only bad thing about this stage I think.....is as you fall in love with this other person, you will generally see more of the "good" things about your partner, than the "bad" things.
As time goes on .......your eyes open wide enough that you see "everything."
Of course, nobody is perfect. But I think in this third stage, if your foundation was built strongly.....the strong connection that you feel towards one another, will supercede anything else.
In a nutshell......I say hang in there! If what you two have is strong, it will survive this.
To me..........loving someone with the "full" of you, is to love them with your entire being. You love them enough to weather the storms and find ways to keep the spark alive.
Good luck and the very best for you both!