Bad thinking only

I have sick with the flu for couple of days and with my period. These two combined get me depression, the period alone does that. But this time it is really bad. I spent last tuesday crying literally all day for no reason and for a reason and simply for everything. I have been trying to get myself together eversince. I am not rushing myself to be better or anything. The problem I have is that my mind keeps thinking of the sadest things, things I miss or things I wish had been different. I tried everything, journaling,meditation, gratuful writing, watching a series, reading, taking a bath, and sleep all that didn't really do anything. I can't take a walk now as I am still sick and get a little bit dizzy, and it is a little cold so I can't stay outside for long.