Postpartum Depression?

So I just had my second son a month ago. With my first I had unbearable postpartum depression. I cried for hours at a time without stopping, and it got so severe I had to be put on medication. Now that I've had my second, I'm not so much depressed as I am angry. I've been have been lashing out for no reason at my family and my husband. I get angry at the littlest things, and I know I'm getting mad for no reason. I just can't control it anymore. I don't know what to do. Thankfully I'm not getting angry at my children, but could this be a type of postpartum depression? Or am I just going insane???