I am tired
The books I've read have always explained blood as smelling "coppery" or "metallic." They're not wrong, but they're not right either. Yes. I could detect that old-penny tang in the air, but there were other things too. They never mention the rot of it. The butcher shop meatiness. The piss and shit part that will undoubtedly be there. Because if there is so much blood you can smell it, then someone is either dead or about to be. A bandaid would no longer help them. Blood doesn't just smell like loose change. I should know. I was covered in it.
Chapter two of my short story Milk
The thing about hitting rock bottom is that you never really know when you are there until you start to build up from it. Or until you are away from it. You can assume that "it couldn't get any worse," but these words are often folly and should be treated in the same way as "Lord Voldemort," (For the muggles - don't fucking say it out loud)