I think you are doing fine, HNU. Try not to be too hard on yourself. You don't deserve it. You deserve to be happy, too. Let it go. We all tend to be codependent around animals. They cannot do all that they need on their own. Someone has to do it for them. You are fine.
Unfortunately, because of my intelligence and energy, I over-accommodate and keep doing it for a lot longer than I really should, because in addition to intelligent and energetic, I'm also very human. It seems that I like being able to say I am making a sacrifice to help someone or something, beyond the point of what's normal. Maybe it makes me feel more competent, but it sure as heck doesn't make me feel good. Therapy has helped in that now I can recognize when this is happening, and stop it before it really goes too far. I was remembering this morning during my work out the time I dated a blind diabetic guy, and the great lengths I went to, to help him, and his guide dog. I have come a long way since then.
It was like I had some kind of slot-machine syndrome. I really want people to be successful or to have more than just one small problem solved, so once I commit to something, I overcommit, even when it's a lost cause, and I seemed to have specialized in lost causes, or in rather, smacking my head against the wall repeatedly. In some cases, such as with my son who was born with the spinal cord disorder, this trait is incredibly useful. If I hadn't stopped trying, and wanting to solve the problem of his intractable incontinence, to get his MRI that he very much needed for diagnosis, he could have had permanent nerve damage and had to live with being incontinent and behind in most gross motor skills the rest of his life. As it was, he got surgery when he was 7, about 3-4 years after I became convinced that his problem was a tethered spinal cord (it was, also thyroid which I also detected something wrong hormonally and kept pursuing that until he got diagnosed when he was 9 and started thyroid replacement...) So tenacity if that's what you want to call it, is a good strength, but it is also very much my Achille's heel. I am stupid like a badger. I latch onto something and then I don't want to let go. The way of the badger. lol. It can be good or it can be bad, if you latch onto someone's boot, then they gonna drag you through the mud.
I think though that I'm still very sensitive, obviously, to people telling me I am somehow less than human or some kind of sociopath for needing to draw the line, to do what it is that preserves my own health and sanity. It's not just financial, but I realized that because of the cost of dog sitter and the anxiety meds for her, and the grooming and feeding and vet care and registration, that I was spending over 10% of my earned income on the dog, and that doesn't include the lost work opportunities, or the fact that a lot of places that I could possibly rent, if I ever need or want to move to a place where we can have more than 1 bedroom (8 year old girl, 12 year old boy, and me,) a lot of places aren't possible because of a dog. Especially one that pees and poops on the floor. Eventually we would have had damages here. First it was just poop but then it became pee as well. Which is a lot more difficult to remove.