can't save new data, and Array to string conversion?

enter image description here

Model in laravel

"Array to string conversion (SQL: update spent_times set updated_at = 2018-10-18 06:02:29, spent_time = 12, percentage = 60.00, task_category = testing where id = 7) ◀"

public static function findOrCreate($plan_id, $data)
{
    $fromDate = Carbon::now()->subDay()->startOfWeek()->toDateString();
    $nowDate = Carbon::now()->today()->toDateString();

    $spent_time = static::where('plan_id', $plan_id)->first();

    if (is_null($spent_time)) {
        return static::create($data);
    }else{
        $new_spent_time = SpentTime::find($plan_id);
        $task_category = $new_spent_time->task_category;

        $new_spent_time->task_category = (['{task_category}' => $task_category, 
                                        '{daily_spent_time}' => $new_spent_time->daily_spent_time,
                                        '{daily_percentage}' => $new_spent_time->daily_percentage,
                                        '{spent_time}' => $new_spent_time->spent_time,
                                        '{percentage}' => $new_spent_time->percentage]);


        $new_spent_time->spent_time = $new_spent_time::where('task_category', $task_category)->sum('daily_spent_time', $new_spent_time->daily_spent_time, $fromDate);
        $request['spent_time'] = (int)$new_spent_time->spent_time + $spent_time->daily_spent_time;

        $new_spent_time->percentage = SpentTime::where('task_category', $spent_time->task_category)->sum('daily_percentage', $new_spent_time->daily_percentage, $fromDate);
        $request['percentage'] = (int)$new_spent_time->percentage  + $spent_time->daily_percentage;
        $new_spent_time->save();
        return $spent_time->update($data);
    }
}

Controller in laravel

in function store, can't save data and can't calculation data by category when create new data, data should be calculated and entered into the table as pict. (KLIK LINK!) => enter image description here

public function store(Request $request)
{      
    $spent_time = SpentTime::findOrCreate($request->get('plan_id'), [
        'plan_id' => $request->get ('plan_id'),
        'daily_spent_time' => $request->get ('daily_spent_time'),
        'daily_percentage' => $request->get ('daily_percentage'),
        'reason' => $request->get ('reason')
    ]);

    return redirect()->route('real.index', compact( 'spent_time'));
}

via Chebli Mohamed