I haven't come across one, but you could try looking on specialized comic websites or social media groups focused on comics. Maybe someone there knows if such a comic exists.
Once there was a boy and a girl. They met at a comic book store. They quickly fell in love and often shared their favorite comics. But one day, the boy had to move far away for his family. The girl was heartbroken. She would look at the comics they once shared and cry. Their love, which started so happily among the comics, ended sadly with distance.
To help a sad person in a comic, you might have a friendly character approach them and have a heart-to-heart conversation. Maybe show them that they're not alone and that there's hope. Or have a magical element that brings a smile to their face and changes their outlook.
Once there was a little dog in a comic. It was always left alone at home while its owner went to work. Day by day, it waited by the door, looking sad. One day, it thought its owner was back but it was just a passer - by. The disappointment in its eyes was heart - breaking.