Feeling useless today

it’s one of those days where I simply can’t do anything. I’m just sitting here, knowing about all of the task that I leave undone today, ignoring them and feeling guilty for not doing a single task. I feel so useless right now and the worst of all is my brain who tells me every 5 minutes how unbelievable useless I am, to make sure I’m not forgetting it. I just feel down and some kind of sad today, without having a reason to feel that way - and the fact that I’m feeling that way for no reason makes me feel even more sad and down. How makes that any sense?!…