Hello Mark, I really empathize with your situation. From a female point of view, I see nothing wrong about what you've been doing. You are a patient husband
I don't really have any solutions on this, but I hope to provide possible reasons why your wife isn't responsive to your needs:
First, women need lots of criteria fulfilled, such as from emotional trust, to physical turn on, to security, to good techniques in bed, in order to really enjoy sex...maybe she cannot define what is lacking for herself.
Secondly, for many women, sex requires a greater deal of "sacrifice." To paraphrase from Christian Carter's analysis on women's mentality on sex, women often feel "conquered" by men in the act of sex. This ignites the biological instinct to stay loyal to a man and proceed to nurture his children. This implies a lot of effort. Therefore women may feel like sex itself is a lot of effort due to this very subtle and underlying mentality.
Or maybe it's simply that getting physically excited takes a lot of effort, or tending to your needs requires a lot of energy, or doing some compromising positions (being blunt here
) is tiring for her. Of course, it's not your fault, but you have lots of work to do or changes to you need to adapt to, since it's possible that she doesn't feel rewarded, emotionally or physically, after all that work.
Third, your wife thinks sex is only for your own good. From the flower example, she only choose to believe that you do things to exchange for sex. Tell her that's not the real value of sex. Sex is mutual, not some trade. Sex should be for her own good too. So far it seems she cannot/refuse to benefit from sex.
Fourth, deep down in her heart, she doesn't realize how important sex is to you.
Finally, if your wife naturally have low sex drive, it will remain really difficult for her to be responsive to your needs. It'll be ideal if she shows more affection or care about your needs more, but she can't do much sexually. Imagine if you have to eat more when you are completely full. It will make you more disgusted than happy. She may feel "constantly full."
I really hope this will somewhat help you. I will pray that your frustration will be dissolved.