Get that help, get the meds if she needs them. This is not about your feelings. I wasn't diagnosed with ADD until I was an adult, and I can tell you truthfully, my life would have been vastly improved if AD(H)D had been "invented" in the UK in the 1970s and 1980s.
I don't have a bad life now, I have a post graduate level of education, friends, successful relationships and so on, but OMG.....what a battle.
I'm a big fan of Ritalin. If it works for you, it transforms your life, your thinking, your emotions. It doesn't flatten your feelings at all, it helps you to take a step back from your (often) very fine-tuned and painfully oversensitive feelings and THINK before you jump in at the deep end, or react angrily to non-existent insults or slights. This costs ADD people a lot of friends, and a lot of time over the years.
At the moment, your DD is four, so the slow tightening of the thumbscrews that is undiagnosed AD(H)D isn't really happening, but it may well do, if she has it.
It's obvious how angry you are about this, and how hurt you are, but put your thoughts and feelings aside and think practically.
Your DD might not even have AD(H)D...she might just be a bit of a live one who needs the challenge of school.