woocommerce added fee is not calculating always 0 neather total price - wordpress

Question

I have 2 functions. One is to calculate fee (here is part from it that is responsible for calculating fee and saving it into global variable):
function pre_checkout()
{
global $woocommerce;
$section2 ='';
$section3 ='';
$section2 = sanitize_text_field($_POST["user_data"]["section2"]);
$section3 = sanitize_text_field($_POST["user_data"]["section3"]);
$how_many_months = preg_replace('/\D/', '', $_POST["user_data"]["section1"]);
$boxToFind = '';
if(($section2 == 'toy_yes') || ($section2 == 'toy_no'))
{
$boxToFind = sanitize_text_field($_POST["user_data"]["section1"]);
}
else{
$boxToFind = sanitize_text_field($_POST["user_data"]["section1"].$_POST["user_data"]["section2"]);
}
WC()->cart->empty_cart(true);
$boxesLookupTable = array(
//susbscriptions
'small1month'=>'112',
'medium1month'=>'113',
'large1month'=>'114',
'small6month'=>'115',
'medium6month'=>'116',
'large6month'=>'117',
'small12month'=>'118',
'medium12month'=>'119',
'large12month'=>'120',
//gifts
'gift1month'=>'133',
'gift3month'=>'134',
'gift6month' =>'135',
'gift12month' =>'136'
);
$productId = $boxesLookupTable[$boxToFind];
// echo $productId;
//check if product already in cart
// if no products in cart, add it
WC()->cart->add_to_cart($productId,1);
if($section2 === "toy_yes"){
$product = wc_get_product($productId);
$price = $product->get_price();
$toy_price = 4.99;
unset($_COOKIE['product_price_with_toy']);
setcookie('product_price_with_toy',$toy_price*$how_many_months,time() + (86400 * 30),"/");
// WC_Cart::add_fee( 'Gift Fee ', $product_price_with_toy,false, false );
/* "gift"; */
}
if($section3 === "toy_yes"){
$how_many_months = preg_replace('/\D/', '', $_POST["user_data"]["section2"]);
$product = wc_get_product($productId);
$price = $product->get_price();
$toy_price = 4.99;
unset($_SESSION['product_price_with_toy']);
$_SESSION['product_price_with_toy'] = $price + $toy_price;
unset($_COOKIE['product_price_with_toy']);
setcookie('product_price_with_toy',$how_many_months * $toy_price,time() + (86400 * 30),"/");
// WC_Cart::add_fee( 'Gift Fee ', $product_price_with_toy,false, false );
/*"subscription"; */
};
$items = WC()->cart->get_cart();
global $woocommerce;
$cart_url = wc_get_cart_url();
$checkout_url = wc_get_checkout_url();
foreach($items as $item => $values) {
$_product = $values['data']->post;
?>
<div class="dropdown-cart-wrap">
<div class="dropdown-cart-left">
<?php echo get_the_post_thumbnail( $values['product_id'], 'thumbnail' ); ?>
</div>
<div class="dropdown-cart-right">
<h5><?php echo $_product->post_title; ?></h5>
<p><strong>Quantity:</strong>
<?php $product = wc_get_product($productId);
woocommerce_quantity_input( array( 'min_value' => 1, 'max_value' => $product->backorders_allowed() ? '' : $product->get_stock_quantity() ) );
?></p>
<?php global $woocommerce;
$currency = get_woocommerce_currency_symbol();
$price = get_post_meta( $values['product_id'], '_regular_price', true);
$sale = get_post_meta( $values['product_id'], '_sale_price', true);
?>
<?php if($sale) { ?>
<p class="price"><strong>Price:</strong> <del><?php echo $currency; echo $price; ?></del> <?php echo $currency; echo $sale; ?></p>
<?php } elseif($price) { ?>
<p class="price"><strong>Price:</strong> <?php echo $currency; echo $price; ?></p>
<?php }
?>
<div class="dropdown-cart-right dropdown-checkout-link">
<a class="checkout-submit checkout green-btn text-center" href="#">Order</a>
</div>
</div>
<div class="clear"></div>
</div>
<?php }
die();
}
add_action('wp_ajax_pre_checkout','pre_checkout');
add_action('wp_ajax_nopriv_pre_checkout', 'pre_checkout');
Next i have woocommerce action:
function add_cart_fee() {
$chuj = $GLOBALS['product_price_with_toy'];
WC()->cart->add_fee( __('Extra Gift Fee', 'woocommerce'),$chuj );
}
add_action( 'woocommerce_cart_calculate_fees', 'add_cart_fee' );
And basicaly toy fee is always 0 when im using session, global variables - only through cookies is passing values to action - i dont understand why woocommerce / wordpress is wiping global value that ive set inside my calculation function. Or maybe someone know how to update the total price with using hooks and actions, that would be even better than using fee field.