Spend some time working on why the relationship is on again off again. In your posts you cite “stupid reasons” for the offs and no reason for the on again.
Look at it this way: Do you love her enough to make it work? So far, the answer to that is no. Right now, on the face of it, neither of you cares enough to stick when there is a problem or to commit to working through issues together instead of walking out.
Why is that?
If it is because your feelings for each other are deep, but not deep enough, then you need to move on.
If it is that you love one another, but fear total intimacy or have baggage that impacts you in your current relationship, then you may want to work on it. I suggest doing that with a counselor.
Finally, why are you doubtful about opening up on your feelings with her? Honest communication is the basis for any meaningful relationship.