For lack of a better place to ask for advice, I'm going to continue to use this thread for marriage advice even though Bosk will likely point out that it wasn't the original intention of this thread. I honestly don't know where else to turn, so I appreciate your advice.
*all of that*
Sorry... that got kinda long.
I'll bite. You asked for some advice, and I'll give you my two cents. Take from it what you will. I'm also 57. Things do slow down; although they don't have to stop completely. But here goes. You may not like what you hear, but I have been there as well. So, I have some experience here.
You unpacked a lot there. But you also gave some real clues that I think you are missing, or overlooking. I would suggest first of all that you are confusing initmacy with sex. Surely the act of sex is an intimate act, but there are a lot of ways to be intimate without having sex. Have you stopped to think of ways that your wife may want to express or does express her love or intimacy without actually having sex with you? Maybe she too doesn't know how to separate the two, and so now you are both stuck so to speak.
Have you thought of all the other ways she expresses her love for you without having sex? You didn't mention what type of mother she is. Or is she a faithful, and kind, and loving wife in other ways? Is she someone who you can count on to be there when it's you against the world? Does she have your back in other ways in the marriage? Does she still laugh at all of your stupid stories after you have told them for the 1,000th time? Does she encourage and support you? All of these things are incredibly important.
I'm not suggesting that no sex is good. But you didn't say you had NO sex. You are basically saying that because she won't perform to your level of the ideal sex life, then it's her fault, and things are bad.
Have you asked yourself why you seem to think the single greatest thing she can do is have sex with you? Have you considered how she feels having to reject you all the time? Have you considered how she is probably thinking,"He says he loves me, but if he did why can't he see that perhaps I'm hurting inside?"
And you are completely overlooking the single greatest issue between the two of you.
" I know she knows she should do it, but she doesn't feel good enough about herself to do it."
First, why do you say, I know she knows she should do it? She isn't your property, right?
And secondly, the fact that she is telling you that she doesn't feel good about herself is the key here.
Imagine... she had a couple of kids. She probably works, and tries to help manage the house. She has probably put on some pounds. There is the stress of a global pandemic going on. Women are constanly bombarded in focusing on their self image and worth in society based on their looks. She is maybe second guessing her career choices. Always comparing herself and her life to her peers. And she has told you that she doesn't feel good about herself. But instead of trying to help her, or be understanding, you come at her with "Why won't you lick my taint like you did when we were 20?" or whatever. I don't mean to be harsh, and I'm not trying to diminish your needs in any way, but the sad reality is if you entered into your marriage or relationship and thought your sex life was going to only always be "ideal", life just doesn't work that way very often, and your comments come off as being a bit selfish.
What ways do you go out of your way to make her feel sexy? And I'm not talking about telling her she has a nice ass, or that you want to fuck her. There a tons of ways to reassure her and make her realize she is still sexy to you without engaging in or expecting sex. Work on your own relationship initmacy skills.
Lastly, if you feel all you do is fight, then I'd suggest counseling for the two of you, or maybe go yourself. Tell her you want to work on some skills that will make you a better husband and partner, and go to a few sessions by yourself. I'll bet you'd probably learn a few things about yourself and at the very least gain some clarity on how to respond in a more positive way to your situation.
Whatever you do, don't suggest that she has the problem and she needs therapy because she is somehow broken.
But do something. Don't wait until you both resent each other, and despite your best efforts it's too late. Especally since you still love her.
I have been there. It doesn't end well if you ignore it, our are unwilling to change and adapt.
And I have also had a pretty crazy past. I had a real issue with sex and intimacy for a long time. I have slept with probably 1,200 women give or take a couple hundred. I had a lot of fun. But that is not bragging. It took me a long time and lots of therapy to come to grips with how badly I felt about my promiscuity. No woman was off limits to me. I helped ruin more than a few marriages and dozens of relationships, and never let myself get close enough to anyone to know how great they were outside of bed. Fun? Sure...Until it isn't enough anymore-- and let me tell you, I wouldn't trade the healthy intimacy, the partnership, and support from a loving, caring wife now, for all the pussy in the world. Making your sex life the priority and chasing down everything that moves is lonely as fuck. So she only has sex with you once a week instead of three. There are much worse fates.
Good luck