Nevermind, I managed to work it out on my own, thank you anyway
I changed this line:
echo $this->currencyHelper->format($this->order->order_shipping_price,$this->order->order_currency_id);
To this:
echo $this->currencyHelper->format($this->order->order_shipping_price-@$this->order->order_shipping_tax,$this->order->order_currency_id);
In Views/Order/Show (Front end template) and Views/Order/Show_Additional & Views/Order/Invoice (Back end template) and finally in the Preload section of the email.
And for the checkout/cart of the website I changed this line:
} else {
$shipping_price += $shipping->shipping_price_with_tax;
}
To this:
} else {
$shipping_price += $shipping->shipping_price;
}
In Views/Checkout/Cart (Frontend template)