Help me finalize a contact form on theme I am building

Ok, first of all, this is going to be a huge amount of code. Sorry for that. I am not finding a way to make this contact form on my theme work.

Here is the form itself:

<!-- Contact Section -->
<section id="contact">
<div class="container">
<div class="row">
<div class="col-lg-12 text-center">
<h2><?php echo get_theme_mod('contact_title', 'Contact Us'); ?></h2>
<hr class="star-primary">
</div>
</div>
<div class="row">
<div class="col-lg-8 col-lg-offset-2">
<form name="sentMessage" id="contactForm" novalidate>
<div class="row control-group">
<div class="form-group col-xs-12 floating-label-form-group controls">
<label><?php _e( 'Name', 'bootfreela' ); ?></label>
<input type="text" class="form-control" placeholder="Name" id="name" required data-validation-required-message="<?php _e( "Please, enter your name.", "bootfreela" ); ?>">
<p class="help-block text-danger"></p>
</div>
</div>
<div class="row control-group">
<div class="form-group col-xs-12 floating-label-form-group controls">
<label><?php _e( 'Email Adress', 'bootfreela' ); ?></label>
<input type="email" class="form-control" placeholder="Email Address" id="email" required data-validation-required-message="<?php _e( "Please enter your email address.", "bootfreela" ); ?>">
<p class="help-block text-danger"></p>
</div>
</div>
<div class="row control-group">
<div class="form-group col-xs-12 floating-label-form-group controls">
<label><?php _e( 'Subject', 'bootfreela' ); ?></label>
<input type="text" class="form-control" placeholder="Subject" id="subject" required data-validation-required-message="<?php _e( "Please enter your subject.", "bootfreela" ); ?>">
<p class="help-block text-danger"></p>
</div>
</div>
<div class="row control-group">
<div class="form-group col-xs-12 floating-label-form-group controls">
<label><?php _e( 'Message', 'bootfreela' ); ?></label>
<textarea rows="5" class="form-control" placeholder="Message" id="message" required data-validation-required-message="<?php _e( "Please enter a message.", "bootfreela" ); ?>"></textarea>
<p class="help-block text-danger"></p>
</div>
</div>

<div id="success"></div>
<div class="row">
<div class="form-group col-xs-12">
<button type="submit" class="btn btn-success btn-lg"><?php _e( 'Send', 'bootfreela' ); ?></button>
</div>
</div>
</form>
</div>
</div>
</div>
</section>

Now, the Js file that handles it (jqBootstrapValidation):

(function($) {

$("input,textarea").jqBootstrapValidation({
preventSubmit: true,
submitError: function($form, event, errors) {
// additional error messages or events
},
submitSuccess: function($form, event) {
event.preventDefault(); // prevent default submit behaviour
// get theme path
var stylesheet_directory_uri = ContactMe_uri.templateUrl;
// get values from FORM
var name = $("input#name").val();
var email = $("input#email").val();
var subject = $("input#subject").val();
var message = $("textarea#message").val();
var firstName = name; // For Success/Failure Message
// Check for white space in name for Success/Fail message
if (firstName.indexOf(' ') >= 0) {
firstName = name.split(' ').slice(0, -1).join(' ');
}
$.ajax({
url: stylesheet_directory_uri+"/inc/contact-me.php",
type: "POST",
data: {
name: name,
subject: subject,
email: email,
message: message
},
cache: false,
success: function() {
// Success message
$('#success').html("<div class='alert alert-success'>");
$('#success > .alert-success').html("<button type='button' class='close' data-dismiss='alert' aria-hidden='true'>×")
.append("</button>");
$('#success > .alert-success')
.append("<strong>Your message has been sent. </strong>");
$('#success > .alert-success')
.append('</div>');

//clear all fields
$('#contactForm').trigger("reset");
},
error: function() {
// Fail message
$('#success').html("<div class='alert alert-danger'>");
$('#success > .alert-danger').html("<button type='button' class='close' data-dismiss='alert' aria-hidden='true'>×")
.append("</button>");
$('#success > .alert-danger').append("<strong>Sorry " + firstName + ", it seems that mail server is not responding. Please try again later!");
$('#success > .alert-danger').append('</div>');
//clear all fields
$('#contactForm').trigger("reset");
},
})
},
filter: function() {
return $(this).is(":visible");
},
});

$("a[data-toggle="tab"]").click(function(e) {
e.preventDefault();
$(this).tab("show");
});
}(jQuery));
/*When clicking on Full hide fail/success boxes */
jQuery('#name').focus(function() {
jQuery('#success').html('');
});

On my functions.php file, I have this piece of code, to get theme path for JavaScript file.

function get_theme_directory_uri() {
$stylesheet_directory_uri = array( 'templateUrl' => get_stylesheet_directory_uri() );
wp_localize_script( 'contactMe', 'ContactMe_uri', $stylesheet_directory_uri );
}
add_action( 'wp_enqueue_scripts', 'get_theme_directory_uri' );

Then I have this contact-me.php file:

if( empty($_POST['name'] )      ||
empty( $_POST['email'] ) ||
empty( $_POST['subject'] ) ||
empty( $_POST['message'] ) ||
!filter_var( $_POST['email'], FILTER_VALIDATE_EMAIL ) ) {
echo "No arguments Provided!";
return false;
}

$name = $_POST['name'];
$email_address = $_POST['email'];
$subject = $_POST['subject'];
$message = $_POST['message'];

// Create the email and send the message
$to = "mauroluis@terra.com.br";
$email_subject = "Website Contact Form: $subject";
$email_body = "You have received a new message.nn"."Here are the details:nnName: $namennEmail: $email_addressnnSubject: $subjectnnMessage:nn$message";
$headers .= "Reply-To: $email_address";

wp_mail( $to, $email_subject, $email_body, $headers );

return true;

But it is not working. Someone said that the problem is that WP is not loading.

So I tried inserting this on my contact-me.php file, as suggested:

define( 'WP_USE_THEMES', false );
require_once( $_SERVER['DOCUMENT_ROOT'] . '/wp-load.php' );

But still no good results.

Any help?