Error: connect ECONNREFUSED 127.0.0.1:3306

Pelo amor de deus, já passei mais de 4 horas rodando na internet a solução desse erro e simplesmente não encontro:

servidor rodando na porta 3000
Error: connect ECONNREFUSED 127.0.0.1:3306
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1136:16)
    --------------------
    at Protocol._enqueue (C:\Users\alder\OneDrive\Projetos Node\node_modules\mysql\lib\protocol\Protocol.js:144:48) 
    at Protocol.handshake (C:\Users\alder\OneDrive\Projetos Node\node_modules\mysql\lib\protocol\Protocol.js:51:23) 
    at Connection.connect (C:\Users\alder\OneDrive\Projetos Node\node_modules\mysql\lib\Connection.js:116:18)       
    at Object.<anonymous> (C:\Users\alder\OneDrive\Projetos Node\Api_com_express_e_MySQL\index.js:6:9)
    at Module._compile (internal/modules/cjs/loader.js:1139:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1159:10)
    at Module.load (internal/modules/cjs/loader.js:988:32)
    at Function.Module._load (internal/modules/cjs/loader.js:896:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
    at internal/main/run_main_module.js:17:47 {
  errno: -4078,
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '127.0.0.1',
  port: 3306,
  fatal: true
}

Segue o código

const customExpress = require ('./config/customExpress');
const conexao = require ('./infraestrutura/conexao'); //chamando a conexao com o mysql
conexao.connect (erro => 
    {
    if (erro) {
        console.log (erro)
    }
    else
    {
        console.log (`conectado com sucesso`)
    }
})
const app = customExpress ();

app.listen (3000,() => console.log('servidor rodando na porta 3000'));

const mysql = require ('mysql') //chamando o mysql

const conexao = mysql.createConnection ({ //coloca as bases da conexão
    host: '127.0.0.1',
    porta: 3307,
    user: 'root',
    password: 'adm',
    database: 'agenda-petshop'
})

module.exports = conexao;