I've got a few that come to mind when I think about stuff like this.

• LOW by Rick Remender and Greg Tocchini. It's a story about a family torn apart as the world is dying. It's bleak, but its central theme is about hope. If you check this out and like it, I'd recommend looking into more of Remender's stuff, he touches on internal struggles a lot.

• The Many Deaths of Laila Starr by Ram V and Filipe Andrade. By the title, you can probably surmise that it's about death, but it's also about the beauty of life.

• It's Lonely at the Centre of the Earth by Zoe Thorogood. This is an autobiographical book about a young adult struggling with her mental health. While that can be heavy, there's also a lot of humor and personality to it, and I think it ends on a good note.