Freaking out

So my mother is leaving in four days after being here for two and a half months and I am starting to freak out about being alone with two kids. I know many people who are doing great at it by themselves and my rational self knows I can do it too but it's my irrational self that is causing me trouble. Stuff like what do I do if they are both crying?, how do I do Aidan's nap?, and how do I get anything else done? are running through my mind right now. When I am nursing how do I keep Aidan out of trouble and occupied? I know I'll figure it out but I just needed to vent about it.