Depression or something else? **Kind of long post/questions at the end

I'm a ftm and I'll be 37 weeks exactly tomorrow. The past few days have been extremely rough. I've lost my appetite and don't find interest in anything anymore. I'm so exhausted but can't sleep. I stopped taking care of myself and have had trouble remembering my pills/vitamins. And above all else I've been crying over everything and nothing. Fresh air hasn't helped and I finally showered today but it hasn't helped either. Someone told me this could be a sign that I'll go into labor soon because I've also been nesting for hours at a time till I can't stand to move. I guess my question is have any of you moms out there experiences an extreme mood change before labor? What can I do to fight off these feelings?