All data in RDS on my account has been deleted, how can I recover it?

If you have snapshots, try restoring from snapshots. [1] [2]

[1] I accidentally deleted my Amazon RDS for MySQL instance
https://aws.amazon.com/premiumsupport/knowledge-center/rds-mysql-accidental-delete/?nc1=h_ls

[2] Restoring from a DB snapshot - Amazon Relational Database Service
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_RestoreFromSnapshot.html

Hello,

Only way to recover is by restoring the snapshot or if you have its native engine dumps stored anywhere.