Convert sql to eloquent

How can I convert this code sql into eloquent ?

SELECT
    CONCAT(FLOOR(sum(diferenca)/60),'h',MOD(sum(diferenca),60),'m') as tempo
FROM
(SELECT
    TIMESTAMPDIFF(MINUTE, m1.created_at, min(m2.created_at)) as diferenca
FROM
    mensagens m1
JOIN
    mensagens m2 ON m1.remetente_id = m2.destinatario_id AND m2.remetente_id = m1.destinatario_id AND m2.created_at > m1.created_at
GROUP BY
    m1.remetente_id,
    m1.destinatario_id,
    m1.created_at,
    m1.id) AS table1
WHERE
    (SELECT
        MIN(id)
    FROM
        mensagens
    WHERE
        destinatario_id = 2);

I tried the form below, but it is giving error because it is treating all select of concat as a column, and I was also in doubt on how to mount join when you have 4 parameters. >

$mensagem = Mensagem::whereIn('id', function($query) {
     $query->selectRaw('TIMESTAMPDIFF(MINUTE, m1.created_at, min(m2.created_at)) as diferenca')
        ->from('mensagens as m1')
        ->join('mensagens as m2', 'm1.remetente_id', '=', 'm2.destinatario_id')
        ->where('m2.created_at', '>', 'm1.created_at')
        ->groupBy('m1.remetente_id', 'm1.destinatario_id', 'm1.created_at', 'm1.id');
     })
     ->where(function($query) {
           $query->selectRaw('min(id)')
                ->from('mensagens')
                ->where('destinatario_id', 2);
     })
    ->select("CONCAT(FLOOR(sum(diferenca)/60),'h',MOD(sum(diferenca),60),'m') as tempo")
      ->get();