Getting Date Difference Since Created_At

Hello.

I need to get a date difference since the created_at until today. I know that i can use carbon for it but i don't know the exact syntax or the correct way to do the whole calculations. I tried doing something like this :

@foreach($transaction->comments as $comment)
    //some views

    Date Differences : {{ \Carbon\Carbon::now()->$comment->createdAt->diffForHumans() }}
@endforeach

But it just returned the comment Model, not the createdAt value which i intended...

Any help is really appreciated !!