Get count on relationship for each row

I have three tables with working relationships set up in the model's.

1. narcotic_wastes (holds forms for each time an employees wastes a form)

2. controlled_substances (Holds medication data of each medication vial on hand) joined to narcotic_wastes by vial_id.

3. medications (Holds medication names) joined to constrolled_substances by id

I am trying to query a count for each medication used each month for the last 12 months.

I have started to build the query but have got stuck at grouping by each medication.

$nw = NarcoticWaste::with(['vial' => function($query)
        {
            $query->select('medication', DB::raw('count(*) as use_count'));
            $query->groupBy('medication');
        }])
            ->get();
            
        if($nw->vial->isEmpty()){
            
        }else{
          foreach ($nw as $nw)
        {
            $nw->medication->count();
        }  
        }

I get an error showing collection 'vial' does not exist.

When I run this query;

select `medication`, count(*) as use_count from `controlled_substances` where `controlled_substances`.`id` in ('259') group by `medication`

I get a response of medication 1 and use_count 1. This is the correct response as for their is only one record.