Hormone drop off

I was cranky all month. When I say cranky, I mean a straight b*tch. I hated everyone. Every time someone talked to me, I was pissed at them. I'm not proud of this, but I called my SO stupid a couple times in one day once my period started. I didn't even mean to.. I would be talking and end my sentence with "stupid" and then i would say "Why did I say that? I don't even mean it?" I ended up in the ER the next night and got a huge shot in my hip and I was in and out and typed "shut the f*ck up" in a message to him and sent it. He was the nicest ever when he replied, and when I read what I had said to him I cried and apologized for hours. Now I'm on tons of medicines and have been feeling a little better. Anyways, I have been the most loving these past couple days. My period ended today and I've been laughing and smiling all day. Back to my normal self. I've been telling him I love him and how perfect and handsome he is just like I always do. Could being sick have made me such an ass for an entire month? I'm not looking for an excuse, I own up to the things I said even if I don't remember them. I just want to know. Has anyone else ever been really mean and then the next day woken up and been super nice? I have PTSD but my mood swings have never been this bad. I'm tempted to get my IUD removed because of how moody I was last month. Any thoughts, ideas? Please don't tell me I'm a bad girlfriend because I feel bad enough and I asked my SO what I could do to be a better partner and he said "stop worrying about it"!