You know sometimes when she is saying that my I love you doesn't sound sincere or that I'm not loyal I just want to scream and ask her number "Who would put up with this if they didn't love you". I don't say that. sometimes i really want too tho.
You are being triggered, and she knows that, that is why she says it, she is testing you. She can read your emotions regardless of what you say. The only way around this is to learn the lessons here to reduce your own tendency to be triggered.
Flip flopping moods for no reason that is apparent to you is normal, and she will let her mood out on you whether it has anything to do with you or not.
You cannot change what she does, only how it affects you and how you react to it.