Enfieldshop.ru Full Debug & Repair

I run Enfieldshop.ru and recently asked a developer to add /ktm and /bajaj sections. Since his changes went live the whole site has started to misbehave—slow page loads, endless database queries, and links that randomly break... (Budget: ₹600 - ₹1500 INR, Jobs: CSS, Debugging, HTML, MySQL, Nginx, PHP, Web Development, Website Audit, WordPress)