Your Hobby plan upgrade went through and the $5 payment was captured, but upgrading the plan does not automatically resize existing volumes. Your Postgres volume is still at its original 500 MB and is ~99% full (494 MB used), which is why the service is crashing. You can expand it up to 5 GB by clicking on the volume in your project canvas, then using the Live Resize option in the volume settings. Once resized, redeploy the Postgres service and it should recover.

It worked, thank you very much!