Watakoi has straight up physical and emotional abuse going on with that secondary couple.

You made me realize the genre is so sparse that most of what I’ve found has been manga. The single anime I can think of off the top of my head word be Signs of Affection, but it’s college and only the first season is out. As for manga:

Complete:

• Sweat and Soap - they get together early in the story and actually have sex and communicate about their problems
• Telework Yotabanashi - one volume, this is what got me introduced to the author of Sweat and Soap.

Ongoing:

• Smoking Behind the Supermarket with You. This one is much more drawn out, but the main characters are so earnest and emotionally supportive of each other.