Here's something to consider.
A lot of women don't like to be directly asked for a physical connection; they like for an expression of affection to organically grow into it. If a question is posed earlier on, it feels like water being thrown on a fire. It has nothing to do with their husband or the love they feel towards their husband and is not a feeling of rejecting their husband whatsoever, but it might have something to do with women not having testosterone.
Also, a lot of women prefer multiple expressions of affection (perhaps 20+ incidents), and very importantly, some of those expressions should organically become sensual but not progress further, between the times of the mutual physical expression of love.
We women are creatures that naturally tend toward of negative self talk about ourselves so our husbands have the very important role of cementing his affirmations of us constantly. These expressions do that and warm our hearts towards the desire of a physical connection. We don't have testosterone to drive us to that; our hearts are the only thing we have to drive us to physically connect.
You too, indulge in negative self talk - but she likely has magnitudes more. Imagine if she told you 20x about how she loved and desired you between the 1x she wasn't in the mood for sex. The 1x wouldn't bite as much. You are doing similar for her so she has an overwhelming assurance of your love, affection and attraction to her. This will usually increase a woman's appetite for sexual frequency.
It's really important to keep at the forefront of your mind when you have these feelings is that she has never said her lack of mood for sex has anything to do with a personal rejection of you, so it's very important to purposefully reject this type of self talk. If she is initiating 2x per month on average, it is EXTREMELY unlikely that she feels any of that towards you. Women who do generally can't initiate sex.
There could be 100 reasons for her not feeling ready for the physical activity required of the connection ranging from a digestive event that is in the works, to needing a shower but feeling too lazy to take one (remember, she doesn't have testosterone driving her), having something else bothering her that is distracting her focus and the list can go on and on.
An area of self discipline you could work on is to not ascribe thoughts or motives to her that are not expressed.
Here is an article about what happens in marriages when the ascriptions are expressed (which you are not doing), but they are just as harmful when they are thought and the other person is mentally blamed without the other person knowing anything what they are being blamed for. They still erode the love in the marriage.
I can double-dee-guarantee you that anytime my husband thought he knew what I was thinking he was FAR afield of what I was actually thinking. I've experienced this many times so I know to never assume what he is thinking either. To do so is an unspoken disrespectful judgement which harms my love for him even if he isn't aware of what I'm thinking.
Disrespectful Judgments
I'm very scrupulous about disciplining my thoughts to not think any negativity about my husband's thoughts, motives or intentions unless he specifically expresses such. This is a technique that has been proven to prevent problems in marriages.