Relationship crossroads question. Help me think this through?

I’m in a LTR. Lately, I’ve been feeling empty and unhappy. This emptyness and unhappiness is less about replacing my partner with someone else and more about getting back in touch with a positive/vibrant version of myself. There’s a part of me that wants to take time to just do some individual course correction and then go back out there and live.

My partner and I love each other, but we are not alike. Our common ground isn’t too big, and so we’ve relied on romantic love, dutiful compromise, and some mutually agreeable routines to do the heavy lifting when it’s been required. (We’ve also been able to rely on a hefty cushion of money, which maybe doesn’t buy happiness, but it sure can buy complacency.) Nowadays, that kind of enthusiasm is pretty thin. (Coincidentally, so is the $.)

Naturally, this is all changing our dynamic. To add to the mix of problems, my partner is on her own version of mental and emotional life support. She has carried a burden of too many obligations toward others (family members, her employer, me, etc.) and for various reasons has consistently deferred dealing with putting these relationships in their proper context or making room for her own needs or dropping obligations that aren’t necessarily her responsibility and asking those responsible to pick up the slack. This general situation has gone on for years, and over the years, I’ve tried countless times to encourage her to think through how to make healthier changes, but she hasn’t made any and she hasn’t felt like making changes is a possibility. She’s had moments of breaking down in the past after being pushed to the limit over this kind of stuff, but then she gets over it and moves on. Lately, though, she’s less inclined to get over it. So it’s a problem that seems to be coming to a head—at least more than it has in the past.

I’m burnt on this. I’ve had enough of indulging her moods and having to walk on eggshells with certain topics and having nothing get better after so much effort. Not that I’m a warm cup of tea, either, mind you—I’m a pain in the ass as well, but lately, I’m looking back at our time and feeling like I’m done with living dysfunctionally and sacrificing the things that normally make me feel alive and happy. This is drudgery, and at this point it’s drudgery without obvious virtue.

My problem is that a) I don’t quit relationships—I don’t know that I’ve ever initiated the termination of a relationship and b) I’m stuck between participating in this sickness and my feelings of obligation to step up and care for my special someone in her time of need, especially someone who has given me the world a few times over. I don’t quit relationships, because somewhere in my brain I equate it with being the bad guy (or something). And, my partner frequently expresses her own feelings of shame/self-loathing or whatever as orneriness. So, while I am dealing with an unpleasant person and unpleasant, unfun, disassociated behaviors, I know when I am able to step back that this person is hurting underneath.

Despite this, I’m tired of the behavior. I don’t want to deal with it anymore, and I want to just spend time making positive changes for myself and enjoying the company of people who feed me.

So, how do I think this through? I’m not looking for “just quit” or “just stay” type responses. What I need is some thought or some experience that will help me see that some course of action will make things better in the long run. I feel a debt of loyalty to this person, but I also feel like my life is slipping away unfulfilled.

I should add that in the past, I was content wallow in unfulfillment—it’s been a very dominant and consistent theme in my adulthood, so I am also wary of the notion that leaving this relationship will in and of itself result in instant fulfillment. That being said, however, I feel like I am swimming upstream with the status quo.

Your thoughts are appreciated. Please note I may decline to respond with more detail.