Tired

A bad start to the week.  Woke up on Monday so, so tired - not physical exhaustion, entirely mental exhaustion.  Didn't feel like doing anything - didn't want to get out of bed, didn't want to work, didn't want to cook, didn't want to go outside, didn't want to play video games or even watch a film.  By far the worst day I've had since the stay-at-home order came into effect.  Decided to take a "mental health day".  Could do with a "mental health week" off work really, but I'll take what I can get and save my sick days in case I actually need to use them them later in the year.  And I feel better today - better enough to actually get some work done anyway.  I don't know if there was anything specific that set me off, does there need to be?  It's difficult to spin it any other way, but everything is depressingly sh*t at the moment.