Whenever I have heavy traffic to certain page Magento adds "-1" to the URL and if the traffic maintains it adds "-1-1" and so so on. This makes it impossible to link back to my website.
The only time Magento will append
-1 to a URL is when you duplicate a product - it won't do it in any other circumstance.
Your issue will be caused by custom code.
Follow the debug guide to the letter, Fundamentals for debugging a Magento store