Pace yourself. There's always more work tomorrow no matter how much you get done today. Don't set an impossible pace dealing with the queued up work you can't meet, because you will try and hold yourself to it, and so will those around you. It's better to finish something earlier than promised once in a while than to be behind once in a while. Don't let the burden of being a superhero at delivering things fast, and the worry of what happens when you finally can't, wear you down.
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
Pace yourself. There's always more work tomorrow no matter how much you get done today. Don't set an impossible pace dealing with the queued up work you can't meet, because you will try and hold yourself to it, and so will those around you. It's better to finish something earlier than promised once in a while than to be behind once in a while. Don't let the burden of being a superhero at delivering things fast, and the worry of what happens when you finally can't, wear you down.