Instagram has become a major distraction for me. I will spend hours upon hours mindlessly scrolling, allowing what little time I could have spent doing things I enjoy to slip away. I don't want to delete the app since I sometimes use it to message people. Is there a way, perhaps using Shortcuts, to check if I'm on Instagram, if so, set a reminder (e.g. "Get off!") to pop up every 10 minutes, and once I'm off, delete the reminder?
You could activate Screen Time (https://support.apple.com/en-us/HT208982) with a limit set to ten minutes per day which would give you a full screen overlay when your time is up, with the opportunity to extend your usage by one minute, fifteen minutes, or for the rest of the day.
Tine limits can be managed on a per app basis.