Maybe recognizing her triggers, or cycles, will make things different. Good for you. Men can be funny, trying to 'fix' things. Dont put so much pressure on yourself, sounds like you are doing great.
It's so nice to hear people talk about love. You know that feeling you are talking about? It being incredible? I would remember that feeling when things get a bit rough. Yup, take a moment and remember that. Powerful stuff.