Sh-t that's no good bro. At the end of the day it's only a job. Don't ever let yourself get to that point again mate. Like Master says mention stress as much as you can and they'll be walking on egg shells to try and accommodate you, I would also suggest taking some leave, just to recharge the batteries and get your mind straight. Tell HR that the solution given to you was to work more unpaid hours. That's just crazy.