As is common to all of us, life's details aren't always pretty. Sometimes we think things through, and acknowledge and respect our feelings and those of our neighbors. At other times, we cut and run and busy ourselves with something else, or someone else's problems, leaving our own problems left untended. Sometimes we present conflicting messages such as regarding whether any abuse took place. Perhaps it's a matter of how abuse is defined. Perhaps it's a matter of wanting to avoid negative comments from others. Infidelity and emotional abuse are serious breaches in a relationship; both require a serious look inward, as seems to be occurring at last. That's an excellent start. You mention that there is a lot of healing (still on-going) on both parts. An honest discussion and apologies all around works better than everyone covering up and hiding, as you both have no doubt experienced. Genesis 3 shows what covering up and hiding got one couple. I think we can all do better than that, if we are honest and face up to things without being prompted. That's generally what allows human to be friends with one another (you have mentioned love, friendship, and happiness being shared, at least at times).
I don't think that money is such an insurmountable issue, or has ever really been (from your description). It seems that you've both always been able to take vacations, including your extended working vacation now. Perhaps, having both separate and joint bank accounts can solve a lot of financial tension. As can having things down in writing, even between you, so that you can easily agree on what you've each committed to. Certainly, you are to be commended for your excellent work ethic: whether in working 70-80 hours a week at Burger King, or volunteering to help take care of your Grandmother. That having been said, that sounds more like brutal slave hours to me if you have no life beyond working, sleeping, and eating. In fairness to all involved, if you included all that you e-mail to as part of JWD, and the others in your life, you do have people that you are talking to, just perhaps more over the internet than face-to-face. A more rural setting versus a more cosmopolitan one can certainly change how you interact with others in your life.
It is wonderful that you love your grandmother so dearly, and have learned things like knitting, crocheting, and baking from her. It sounds like you and your mother have done well with having a medic alert system installed, and helping your grandmother connect with others again so that there are not many days that she is alone now.
Those are some of the things that stubborn, hard-headed women can do for the ones they love. But how can they show love to themselves? One way is by not giving up. Not giving up on those like your grandmother, whom you love so dearly. And in not giving up on yourself or your dear Dave. After all, pobody's nerfect [you got it: nobody's perfect]. After all, you, Amanda, are (present tense) married to him, David.
Perhaps we can start with some of the basics that are often too easily overlooked. What do you really like about Dave? What makes him a keeper in your mind? What do you really like about yourself, that Dave may not know about you yet? What makes you a keeper?
Wishing you both continued success in your modern, real-life marriage. A 3-fold cord is not easily broken.
— Q. Bert, after all.