Before u make any changes, you can check a couple of things real quick:
• In ur AWS billing dashboard, select a bill, expand the CloudWatch toggle and see the CloudWatch cost break down. Is it from log storage or ingesting the log?
• If from log storage, go to CloudWatch console and see which Log Group is using the most storage. If it’s from functions/apis in the SST app, set log retention as @Ross Coundon suggested
• If from log ingestion, check if you are writing a lot of logs in ur functions.