In your widget form’s foreach loop of both seasons and competitoins, You have used
if($competitions == $term->term_id) {......}
and
if($seasons == $term->term_id) {.......}
But it is wrong, use following codes instead of those:
if($instance['competitions'] == $term->term_id) {}
and
if($instance['seasons '] == $term->term_id) {}