You keep replaying it. Looking for the moment it could have gone differently. Looking for the thing you said, or didn't say, or should have said. Looking for the place where you could have changed the ending.
There isn't one. That's not a failure. That's just how this one ends.
The grief is proportional to the love. You can't have one without risking the other. What you're feeling right now is just proof that what you had was real.
These are for the night when it's sitting on your chest and you need someone to just say it plainly.