149900 PHP Optimization and Sitemap

I have a website www.legalty.com. The site is working fine but is not developed in an efficient way. The server crashes when search engines come to crawl it for example. This project is to review the code, understand the problems leading to the slowdown and collapse of the search queries and fixing them making the same queries work efficiently. At the same time you have to develop an site map facilitating search engines to crawl the pages.