Sorry that you have to be in the current situation. But stay calm, and the sky is not falling.
If I understand correctly from your last description, the PIP situation was due to the high expectation from your boss / company and you probably have not been to deliver as expected. Once the “bad” impression is set in your boss’ mind about your performance, do you think your boss would change his impression about you in the very near future after PIP? Most likely not. Many companies might just use the PIP’s as warning signals to terminate / lay off people. And at the end of PIP’s, they can find any reasons to let people go.
So for your situation, immediately start looking for a new job. What your boss outlined in his e-mail could be part of the PIP. Did HR people get involved in? Meanwhile, try your best to complete the tasks your boss discussed with you, and do them well so that at least you can buy more time….
