I agree that every dog is different. I had a terrible time with Princess, my fault mostly. She never gave any indication of having to go. She would sniff for like one second then squat. This would happen right in front of me & I truly felt helpless for a while.
We tried outdoors for a while & she would get in my face and stare at me so I'd take her out. But she still went inside, too, so I tried pee pads.
Now, at 18 months, she's had maybe 1 1/2 months with no pee accidents & she still misses the pad in the bathroom for the other, but it's always in there so I'm pretty happy overall. I know exactly how you feel though, it is stressful. It's easy to read a book, it looks so easy, but in the end you just have to know your baby-and in time you will.