WordPress Redirect based on the prescence of a cookie

I have a tricky situation….
I’d like to check for a cookie. If it doesn’t exist then then redirect to an internal wordpress page, and set a cookie. And then carry on browsing the site. But i get stuck in a loop if the url doesn’t exist. This is what i have so far…any help would be great.

function cookiebasedredirect() {

    // WHEN YOU HAVE FOUND YOUR COOKIE
    if ( !isset($_COOKIE["sevisitor"])) {

        setcookie('sevisitor', 1, time()+1209600, "https://wordpress.stackexchange.com/", "http://localhost/child/", false);       

        // GRABS THE CURRENT PAGE NAME - THIS IS ALSO KNOWS AS THE PAGE/POST SLUG
        $pagename = get_query_var('pagename');

        // PAGE CHECK SO THAT YOU ARE NOT IN AN INFINITE LOOP
        // IN THIS SAMPLE MEDIA-GALLERIES IS THE PAGE YOU WANT TO BE 
        //  REDIRECTED TO IF A COOKIE IS NOT SET, BUT ONCE YOU GET THERE
        // MAKE SURE WORDPRESS DOESN'T EXECUTE THE REDIRECT
        if( $pagename != "about-myself") {          
            wp_redirect( get_site_url().'/about-myself' ); exit;

        } else {


        }


    } else {

    }}
add_action("template_redirect", "cookiebasedredirect");

why not use the init action hook:

function has_my_cookie()
{
    if (!is_admin()){
        //Check to see if our cookie is set if not redirect to your desired page and set the cookie
        if ( !isset($_COOKIE["sevisitor"])) {
            //setcookie
            setcookie('sevisitor', 1, time()+1209600, "https://wordpress.stackexchange.com/", "http://localhost/child/", false);
             //Redirect 
            wp_redirect( get_site_url().'/about-myself' ); exit;
        }
    }
}
add_action('init', 'has_my_cookie');