Worst clients yet 🙄

So I dog sit. I have three dogs of my own and a cat, and I’m currently watching three more dogs. So my hands are pretty full especially since one of the dogs I’m watching is a puppy. I only charged the people 10 dollars a night per dog, because I guess I’m way to nice,which is 3x cheaper than most people. She mentioned something about dropping them off the night before their stay, so I told her I’d only charge her $10 for that night, again just being nice, and went to confirm pick up date, full prices, etc. and she changed the pick up date. It was going to be $550 even with the cheaper prices and the $10 first night discount. She then changed the date to a day sooner.... fair enough. I was going to drop the $10 first night discount though because honestly I was already losing a couple hundred bucks from this job. And she INSISTED that I give her the discount 🤦🏻‍♀️ so I did. Only $20 bucks I guess. But her dogs are absolute TERRORS. Cute as can be, worst dogs I’ve ever sat. The puppy is INCREDIBLY aggressive. It’s always attacking the other two dogs and my own AND it has bitten my husband THREE times now for no reason 😡 I love dogs. They’re my passion, but this is too much. Two of the dogs, the older one and the puppy, are intact males. And they keep marking on EVERYTHING. They’ve marked on my door, my cats scratch post, my rocking chair in multiple spots, my kitchen table, and even a clean basket of laundry I had sitting on the floor by the washer. I also live in an apartment and all they do is BARK and they don’t listen to anything I say. I’ve honestly had to resort to a spray bottle (not even hitting the dog because I don’t want the wet dog smell) but just spraying by them when they do it and it stops them for a minute. I’m getting way too overwhelmed and underpaid for this one 🙎🏻‍♀️ and they only paid half up front, which is fine normally, but they have already gone through half my puppy pads and they all have special routines etc. it’s harder than it sounds. Don’t dog sit unless you have a LOT of patience. I generally do, but this is insane.