there could be something wrong with the nesting, it’s really hard for me to make out. There is a limit to how far you can nest the meta query. Nesting further than the example given in the codex will cause a timeout. I think there is an infinite loop or something else going on. http://codex.wordpress.org/Class_Reference/WP_Query
If you’re nesting is too deep and you can’t reduce the depth, or if there’s just too much for WP to handle the you’ll need to go directly to the database with wbdb https://codex.wordpress.org/Class_Reference/wpdb
