Hey abbi49,
Thank you for using Apple Support Communities!
I understand from your post that you're having trouble setting limits for screen time on a certain app. I'd be happy to help out.
To set limits, you can follow these steps:
Use Screen Time on your iPhone, iPad, or iPod touch - Apple Support
Screen Time gives you a detailed report about how your device is used, apps you've opened, and websites you've visited, any time that you want to see it. Just go to Settings > Screen Time and tap See All Activity under the graph. From there, you can see your usage, set limits for your most used apps, and see how many times a device was picked up or received a notification.
If you turned on Share Across Devices, you can view overall usage across devices that are signed in with your Apple ID and password."
Cheers!