iMessage taking up 600+ GB of iCloud Storage

iMessage takes up a ridiculous amount of storage in iCloud. My top conversation is barely even 20GB, which is why I cant see why it would be this large. The only thing I can think of is that I take a lot of videos since I record my volleyball games, and send them to my teammate via iCloud link. Every iCloud link expires within 30 days. Even still, all of them combined comes nowhere near to 600GB. I don't know what else to do since I share my iCloud plan with my family and I take up almost all of the 2TB storage that we have. Any help would be appreciated.