如何为每个发件人获取最后插入的值？

I know you can get the last inserted id using this $insertedId = $user->id; But I'm trying to get the last inserted value in my view for each sender who sends the data. Just like a inbox it always shown the last message that sent by the sender. How can I show this in my view?

This is my POST where messaging happens.

public function postMessage(Request $request)
{
    $this->validate($request,
    [
        'recipient' => 'required',
        'message' => 'required|max: 2000',
    ]);

    $message = new Message();

    $message->message_content = $request->message;

    $message->save();

    $user = Auth::user();

    foreach($request->recipient as $recipientId)
    {
        $message->users()->sync([ $recipientId => ['sender_id' => $user->id]],false );
    }

    return redirect()->back();
}

Retrieving the values. What I'm done here so far I just retrieve all the user's message. Still don't have an idea how to get the last inserted. Any help how can I achieve this?

public function getMessage()
{
    $recipientLists = DB::table('users')->where('id', '!=', Auth::id())->get();

    $messageResult = DB::table('message_user')->select('messages.message_content', 'users.username', 'messages.id')
        ->join('users', 'users.id', '=', 'message_user.sender_id')
        ->join('messages', 'messages.id', '=', 'message_user.message_id')
        ->where('user_id', '=', Auth::id())
        ->where('sender_id', '=')->get();

    return view ('message.create')->with('recipientLists', $recipientLists)->with('messageResult', $messageResult);
}

Migration (Pivot table)

public function up()
{
    Schema::create('message_user', function (Blueprint $table)
    {
        $table->increments('id');

        $table->integer('message_id')->unsigned();
        $table->foreign('message_id')->references('id')->on('messages')->onDelete('cascade');

        $table->integer('user_id')->unsigned();
        $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');

        $table->unsignedInteger('sender_id')->nullable();
        $table->foreign('sender_id')->references('id')->on('users')->onDelete('cascade');

        $table->dateTime('dateReceived')->default(DB::raw('CURRENT_TIMESTAMP'));
        $table->timestamp('dateModified')->default(DB::raw('CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP'));
    });
}