First off all, OP, you sound like a really nice guy, and it sounds like she has a lot of issues. While it's likely both of you made some mistakes, since everyone does in relationships, in this case it sounds like you weren't the one in the wrong.
Mengy said:
Her reasons confuse me. We haven't really fought much at all in three years, and she says that bothers her. But honestly we haven't had much to fight about, we get along tremendously. I always viewed that as a good thing, but she grew up with parents in a loveless marriage and always fighting, I think part of her equates fighting to love.
DON'T let this bother you!
Fighting does not equate love, it is not necessary to fight regularly in a relationship, as long as both people in it are happy.
My husband and I have been married for 11 years, are still going strong, and I can count the arguments we've had in that time on one hand.
If you get along, can talk to each other rationally when there is a problem, and you simply dislike argueing then there is nothing wrong with your relationship.
It's only a problem if you aren't fighting because one person is always giving in, or hiding their real feelings inside.
Having said that, some people like having a good argument (preferably with good make-up-sex afterwards). Maybe she's one of those, but from everything you've written I think she has a lot more issues going on, and most of them only indirectly involve you.
So don't feel that in the next relationship you'll eventually get into you'll have to force yourself to fight just to keep the relationship going.
Losing your temper can result in saying things you don't mean or in say things in a hurtful way just to spite the other, which is just as bad as hiding true feelings or not being assertive.
If you're a mellow guy, just roll with it, and find a similar minded partner who doesn't need roaring arguments to feel loved.