update reward points and recollect the quote total and list the discount with reward points

Question

I have customized for applying the reward points from a third party Capillary. I want to update the cart total and display by deducting from the reward points after the response from the curl. I have updated the quote in a controller by the code.

protected $cart;
protected $cartHelper;
protected $_customerSession;
protected $_scopeConfig;
protected $_objectManager;
protected $_checkoutSession;
protected $_quoteRepository;
protected $_priceCurrency;

public $fieldId = ["capillary_enable", "capillary_url", "capillary_user", "capillary_password"];
public function __construct(
    \Magento\Framework\App\Action\Context $context,
    \Magento\Customer\Model\Session $customerSession,
    \Magento\Checkout\Model\Cart $cart,
    \Magento\Checkout\Helper\Cart $cartHelper,
    \Magento\Framework\ObjectManagerInterface $objectmanager,
    \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
    \Magento\Checkout\Model\Session $checkoutSession,
    \Magento\Quote\Api\CartRepositoryInterface $quoteRepository,
    \Magento\Framework\View\Result\PageFactory $resultPageFactory,
    \Magento\Framework\Pricing\PriceCurrencyInterface $priceCurrency,
    \Magento\Framework\Message\ManagerInterface $messageManager
) {
    $this->_customerSession = $customerSession;
    $this->_scopeConfig = $scopeConfig;
    $this->_objectManager = $objectmanager;
    $this->_priceCurrency = $priceCurrency;
    $this->_checkoutSession = $checkoutSession;
    $this->_quoteRepository = $quoteRepository;
    $this->cart = $cart;
    $this->resultPageFactory = $resultPageFactory;
    $this->cartHelper = $cartHelper;
    $this->messageManager = $messageManager;
    return parent::__construct($context);
}

public function updateCartPrice() {

    $quote = $this->cart->getQuote();        
    $quoteid = $quote->getId();
    $discountAmount = 4;
    $label = "Redeemed Points";    
    $total=$quote->getBaseSubtotal();

    $canAddItems = $quote->isVirtual() ? ('billing') : ('shipping');     

    foreach ($quote->getAllAddresses() as $address) {
        if ($address->getAddressType() == $canAddItems) {

            $address->setSubtotalWithDiscount((float) $address->getSubtotalWithDiscount() - $discountAmount);
            $address->setBaseSubtotalWithDiscount((float) $address->getBaseSubtotalWithDiscount() - $discountAmount);

            $address->setGrandTotal((float) $address->getGrandTotal() - $discountAmount);
            $address->setBaseGrandTotal((float) $address->getBaseGrandTotal() - $discountAmount);

            if ($address->getDiscountDescription()) {
                $address->setDiscountDescription($address->getDiscountDescription() . ', ' . $label);
                $address->setDiscountAmount(-((float)$address->getDiscountAmount() + $discountAmount));
                $address->setBaseDiscountAmount(-((float)$address->getDiscountAmount() + $discountAmount));
            } else {
                $address->setDiscountDescription($label);

                $address->setDiscountAmount(-($discountAmount));
                $address->setBaseDiscountAmount(-($discountAmount));
            }
            $address->save();
        }
    }
    foreach($quote->getAllItems() as $item){

        $rat=$item->getPriceInclTax()/$total;
        $ratdisc=$discountAmount*$rat;
        $item->setDiscountAmount(($item->getDiscountAmount()+$ratdisc) * $item->getQty());
        $item->setBaseDiscountAmount(($item->getBaseDiscountAmount()+$ratdisc) * $item->getQty())->save();

    }

    $quote->setSubtotalWithDiscount((float) $quote->getSubtotalWithDiscount() - $discountAmount);
    $quote->setBaseSubtotalWithDiscount((float) $quote->getBaseSubtotalWithDiscount() - $discountAmount);
    $quote->setGrandTotal((float) $quote->getGrandTotal() - $discountAmount);
    $quote->setBaseGrandTotal((float) $quote->getBaseGrandTotal() - $discountAmount);


    $quote->setTotalsCollectedFlag(true)->collectTotals()->save();
    $quote->save();

    $this->_checkoutSession->getQuote()->collectTotals()->save();
 }

This is affected in the database.but after refreshing the updated value is coming for the first time and after the api call of

/V1/carts/mine/totals-information

its reverting back to the old details of quote and reflecting in the cart total summary ui. kindly help on this.