Erro após executar nodemon server.js

Gostaria de saber o que pode estar ocorrendo, o código retornado no terminal é este... caso não fique ruim de se ler, vou deixar o link para a imagem do print do terminal. https://imgur.com/9K1qJAt Ao atualizar qualquer informação ele nã atualiza, porém tentei utilizar o node server.js também não funcionou mais.

home@vaio:~/Documents/casadocodigo$ nodemon server.js 
[nodemon] 1.18.4
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `node server.js`
events.js:167
      throw er; // Unhandled 'error' event
      ^

Error: listen EADDRINUSE: address already in use :::3000
    at Server.setupListenHandle [as _listen2] (net.js:1290:14)
    at listenInCluster (net.js:1338:12)
    at Server.listen (net.js:1425:7)
    at Function.listen (/home/home/Documents/casadocodigo/node_modules/express/lib/application.js:618:24)
    at Object.<anonymous> (/home/home/Documents/casadocodigo/server.js:6:5)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
Emitted 'error' event at:
    at emitErrorNT (net.js:1317:8)
    at process._tickCallback (internal/process/next_tick.js:63:19)
    at Function.Module.runMain (internal/modules/cjs/loader.js:745:11)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:743:3)
[nodemon] app crashed - waiting for file changes before starting...
[nodemon] restarting due to changes...
[nodemon] starting `node server.js`
events.js:167
      throw er; // Unhandled 'error' event
      ^

Error: listen EADDRINUSE: address already in use :::3000
    at Server.setupListenHandle [as _listen2] (net.js:1290:14)
    at listenInCluster (net.js:1338:12)
    at Server.listen (net.js:1425:7)
    at Function.listen (/home/home/Documents/casadocodigo/node_modules/express/lib/application.js:618:24)
    at Object.<anonymous> (/home/home/Documents/casadocodigo/server.js:6:5)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
Emitted 'error' event at:
    at emitErrorNT (net.js:1317:8)
    at process._tickCallback (internal/process/next_tick.js:63:19)
    at Function.Module.runMain (internal/modules/cjs/loader.js:745:11)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:743:3)
[nodemon] app crashed - waiting for file changes before starting...