Stay or Go
You've been turning it over for months now — maybe longer. On a good week you can't imagine leaving; on a bad one you can't imagine staying. The relationship (or the job, or the city) isn't a disaster, which is exactly the problem. Disasters are easy to walk out of. This one just leaves you standing at the door with your hand on the knob, unable to open it or let go.
Aristotle, who thought harder about human bonds than almost anyone before or since, would not ask you whether you were happy. He'd ask you what the bond was made of. In the Nicomachean Ethics he sorts our attachments into three kinds. There are friendships of utility — we're bound because the other person is useful to us. There are friendships of pleasure — we're bound because they're enjoyable to be around. And there are friendships of virtue — the rare ones, where we're bound to the person for who they actually are, and wish them well for their own sake.
The first two, Aristotle warned, are unstable by nature. When the usefulness runs out, or the pleasure fades, the bond dissolves with it — because it was never really about the person. Only the third kind lasts, and it takes time and shared character to build. He put the stakes plainly: without friends, he wrote, no one would choose to live, though he had every other good thing. (The line is his; the sorting of motives is his diagnosis, rendered here in plain terms.)
So here is the counsel. Before you decide whether to go, diagnose what you have. Ask honestly: are you staying for what this person does for you, for how they make you feel in good moments — or for who they are, all the way down? A bond of utility that's stopped being useful, or of pleasure that's stopped being pleasant, is telling you something real. But a bond of the third kind — mutual, honest, wishing each other well — is worth a great deal of repair before you reach for the door. The question isn't "am I happy today." It's "what is this built on, and can that foundation hold weight?"
Answer that, and the door usually opens on its own.
Don't ask if you want to leave. Ask what you'd be leaving — and whether it was ever really there.