I had a similar experience when my girlfriend and I adopted a dog. She really wanted a dog and I was fond of the idea. We adopted the first dog we found that met our criteria for size. She was a lot more work than we expected.

We live several floors up in a decent size apartment and she would constantly pee and poop on the floor. We'd take her outside and she'd look up at the sky for about 10 minutes, not peeing or pooping. We'd bring her in, and within 5 minutes she'd go right on the floor. When we were starting to get that under control, she developed an internal infection from an issue with her spay - this required surgery.

After having surgery for that, we had to drain two tubes that would fill with blood and other internal fluids several times a day. She also couldn't be in a space any larger than her crate for the majority of the day and had to wear a cone of shame. I still have flashbacks of the constant banging of that plastic cone against the metal cage and her whining - even though there wasn't anything we could do for her. After she recovered from that, it was back to square one with potty training. After about 2 months of that - 5 in total - things finally got to a consistent pace. Now she is a great dog and listens most of the time. There were many times during the first few months where we regretted adopting her. Looking back now, all that stress and irritation was worth it. Our next dog will probably be an older one though.. lol