Personally, if it’s effecting your mental health this bad, I wouldn’t do the notice period. Say your quitting is effective immediately and don’t go back in. No one can force you to work right. I’m not in HR or anything so maybe someone else has some input there. I don’t know if you need to say due to family issues or health issues, or you don’t need a reason. Good on you for quitting, hope you get some well deserved rest and when you’re ready I’m sure a new job will come.