can barely do anything right now

I am having a really hard time right now. I can't even remember when I last was this bad. I can't focus on much of anything and have been in bed all weekend.  Then this evening I got up to at least watch my son play his video game which was fine but then we moved on to do homework together and that just slammed me right back down to where I was before.  Don't really know what's causing this.  Just trying to hold on and not feel like I'm completely worthless and hopeless.  Trying to not let the emotions consume me.  I hope I can at least find my prescription and get it filled.