Hi mage,
It seems to me that you're focusing on the bad things at the moment. In a smart book I read this advice : don't leave a relationship because of its negative aspects. you would attract the same negative aspects in your next relationship... Don't focus on this negative side. Write down what you find wonderful about her and what you like in the relationship. concentrate only on these positive aspects. Every morning write down more positive things about this (or about everything in your life). The relationship will improve (yes it will, I tested this method, it worked wonders with my bf). THEN, you can decide to stay or to go. Maybe you'll still want to go. But you will be able to take a free decision and won't attract more pain later
Best wishes to you! We're with you