Yep, you can either click your link to get to your public profile which includes a link to all your threads and posts (just by clicking your name in a post or on the whos online list; the memberlist is available but has no link to it), or you can use the search and type in your username. Both work well, but don't bother with bookmarking it or anything since the results are cached and dumped after a couple of hours.
As of PHP 5.5, the MySQL library has been officially deprecated. It is recommended to move to either MySQLi or PDO libraries for your mysql connectivity. See here for help choosing which interface you prefer: http://php.net/manual/en/mysqlinfo.api.choosing.php