Ways to represent character's internal struggles through environment?

Character in my game sufferst from some mental issues (like anxiety), the game itself takes place in character's inner world. I want to focus on exploring this small open world with lots of little events, places and secrets that represent character's state and issues. Like: a city street level with sounds and signs of life but completely empty (represent lonelyness), random knocks on locked doors in the level (represent people who want to get closer to the character but can't get through the mental block), etc. Basically it should play like a Gmod13_hotels map from garry's mod (a level with lots of individual secrets that you need to explore)
So I've been wondering where I can find similar things to get inspiration from, because I need to make a lot of events/places to fill the level

 

Before filling the level with events, consider the architecture of the level. Richard Lyons, the first speaker in this GDC talk: Creating Compelling Characters, does a good job of showing how things like framing and camera angles can make a character feel vulnerable, or anxious, or powerful, etc. Even if the player can move freely in first person, you can still structure the level to make areas feel exposed, confining, etc. It's something you can do at the gray box stage to really lock in the mood of the environment.

 

Yeah, I've already got this, the level feels the way I ment it to and gives the right mood. Now I need to actually fill it

 

Great! If you know people who experience those issues and are willing to be interviewed, they might come up with some surprising suggestions. One person might talk about colors and lighting, while another might talk about ambient sounds. For example, some people combat feelings of loneliness by playing ambient people sounds, such as always having a TV playing in the background. If you were portraying a non-player character, you could show them always having to have a radio or TV on in the background. But if it's the player character, you could deny them that comfort. When they get home and close the door, maybe all the ambient sounds of human activity would end, with no TV to turn on to break the silence.