Survivor's guilt is the mind trying to make sense of arbitrary outcomes. If there's a reason, the world stays predictable — even if the reason is that you're at fault.
It shows up as replaying decisions, feeling you don't deserve good things, or believing you should have gone instead.
The test that helps: would you apply this standard to anyone else who was there? Almost nobody says yes.
Living well is not a betrayal or a debt unpaid. It is the only thing you can still do with the time you have.