Laravel | handle validation error message from AJAX request

Trying to make a simple post on laravel using AJAX. Here is my form :

<form id = "formNewsletter" name="formNewsletter" class="newsForm">
      <div class="wrapperNewsletter">
           <input type="text" name="email" id="email" placeholder="Your email address" />
           <button name="submit" type="submit" class="btn">&gt;&nbsp;&nbsp; Submit Newsletter</button>
     </div>
</form>

Here is my javascript code:

$('#formNewsletter').on('submit',function(e){
        $.ajaxSetup({
            headers: {
                'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
            }
        });
        e.preventDefault(e);
        $.ajax({
            type:"POST",
            url:"NewslettersController/create",
            dataType: "json",
            data: $(this).serialize(),
            success: function(response){
                console.log(response);
            },
            error: function(response){
                console.log(response);
            }
        })
    });

Note that x-csrf-token is declared inside meta tag on head file. Here is the code for controller:

<?php

namespace App\Http\Controllers;

use App\Http\Requests\CreateNewsletterRequest;
use App\Newsletter;

class NewslettersController extends Controller
{
    /**
     * @param CreateNewsletterRequest $request
     * @throws \Exception
     */
    public function create(CreateNewsletterRequest $request) {
        $newsletter = new Newsletter;
        $newsletter->email = $request->input('email');
        $newsletter->remember_token = $request->input('_token');
        if (Newsletter::where('email', '=',$request->input('email'))->count() == 0) {
            $newsletter->save();
        }
        else {
            throw new \Exception('Error! '.$request->input('email') .'already exists on database', Response::HTTP_CONFLICT);
            exit();
        }
    }
}

The problem is that when I submit the form, no matter if I insert any email on form or not, I get on console the following : Object { code: 0, text: "" } EDIT: I've forgot to mention the handler code, on Exceptions\Handler.php that looks as following:

public function render($request, Exception $e)
    {
        if ($request->ajax() || $request->wantsJson()) {
            return new JsonResponse(array('code' => $e->getCode(), 'text' => $e->getMessage()));
        }

            return parent::render($request, $e);

    }

This code works great for exceptions from controller but not for validation errors. How can I handle the validation errors on Handler.php? It seems like getMessage is not working, it doesn't return the validation error message. From the handler I get the right response for this exception: throw new \Exception('Error! '.$request->input('email') .'already exists on database', Response::HTTP_CONFLICT);

via Miril Terolli