Habituation is why the new shoes stop feeling new. It’s also why the bad situation stops feeling bad. Check both.

You adapt to whatever stays the same, and the adaptation does not care whether it is good or bad for you. The new becomes ordinary, which is why excitement fades, and the intolerable becomes normal, which is how people stay in situations they would never have accepted on day one. A fading feeling is not a verdict on the situation.

Ask the day-one question about one thing you have got used to. If you were meeting this now, how would it look. Use it on a habit, a group chat, a way somebody speaks to you. If you would not accept it, that is worth saying to somebody you trust.