In my story, the main antagonist is a being that feeds off of negative emotions. However, I don’t want to make it seem like everyone has to be happy at all times or that it is not okay to feel upset, angry, etc. I want to make it so that the being feeds off of negative emotions that have lingered for a while – things that have festered and built. I also want to make it so that positive emotions aren’t just “happy.” Instead of just negative emotions and being happy, would stuff like that be okay? Thank you!!!
From what you’ve said, I’m guessing there’s a lot you’re trying to do in this story that I don’t know about. However, in itself, just having a villain that feeds on negative emotions won’t send the message that it’s not okay to have negative emotions – just like having vampires in a story doesn’t mean blood is bad.
What matters is how you depict this process and what you show is the solution to this threat. If your characters are trying to defeat the villain by being happy through sheer willpower, that definitely has problems. That’s probably not healthy or possible, and it would probably make some people feel stigmatized. However, if your villain is causing tragedy after tragedy to grow stronger and your heroes are trying to save people or make the world a better place so there’s less negative energy to feed off of, that’s probably fine. I just wouldn’t have them put pressure on any particular person to be happy. Some people are not in a place where they can be happy, and they need to be accepted as they are.
If your goal is to construct a magical reason why your characters needs to air their grievances or otherwise sort themselves out, that’s going to be tricky. It’s common in stories for characters to be put in situations where they have to grow as people in order to accomplish what they need to – but that’s different than telling people they have to not hold a grudge anymore because the grudge itself is feeding the bad guy. The former is driven by the characters and what they want to accomplish, while the latter is a controlling and invasive requirement imposed on them by the outside world. If compelling characters to work through issues is your goal, I would rework it a bit. It’s common for villains to use unresolved emotional issues in mental or social attacks against the heroes. These attacks often force heroes to confront their issues, and once the issues are resolved, the villain loses power over them. The key is to let each character resolve things in their own way, and not tell anyone how they should feel.
I hope that covers what you need.