How do I tell if my workplace is toxic when I've gotten used to it?

The fact that you only notice when you talk to people elsewhere is the whole answer, and it is a common one. Human beings adapt to almost anything if it comes on slowly enough. What would have shocked you on your first day became Tuesday. That is not you being foolish. It is simply how normalising works, one small acceptance at a time, until the abnormal feels like the water you swim in. So your outside conversations are precious, because they are your calibration. When someone from another workplace reacts with surprise or concern to something you describe as routine, do not explain it away. That flash of their surprise is the truth you have lost access to on your own. Write those moments down. They are the measurements you can no longer take yourself. Make a simple, honest list of the things that make outsiders wince. Seeing them together, outside the fog of daily habit, tells you plainly what you are dealing with. You do not have to decide everything at once. But you do get to stop calling harmful things normal, and that clarity is where every good decision after this one begins.