Hi @pixeldynamo
Within your widget code you must find a way to obtain the current $post ID. Then you can get ACF to return the correct data by using the second parameter of teh get_field function.
http://www.advancedcustomfields.com/resources/how-to-get-values-from-another-page/
Most likely you can find the $post with this:
global $post;
$post_id = $post->ID;
Good luck
