If you have so much to complain when you're only seeing more of her than usual, can you imagine how you're gonna live with her for the rest of your lives?
U've been together for 6 years, it's no doubt that you don't want to break up because you're so attach to each other. You don't know how to survive a day without her. But is this reason sufficient enough for you to bear with all those that you've compalined for the rest of your life?
Besides, I think you need to ask yourself do you really love her or you're just used to her being there? Don't be selfish..as you said, you've already wasted 6 years of her youth. Make up your mind now. Yes or no? You cannot decide one day that she's not the one you're looking for and dump her at 30.
I'm not saying you should break up or what, I just think that you need 2 make sure that she's the girl you want to live with for the rest of your life. No buts and no complaints!
Have you tried talking to her face to face? At least give her a chance to defend herself. Remember, it's hard to find a person you love who loves you back. So do appreciate.