Though I don’t know with certainty, it sounds as though you stopped taking your medication without the assistance of the prescribing physician (i.e. “cold turkey”). That is not recommended. Physicians slowly reduce the medication dosage in a safe and controlled manner. They do this because stopping “cold turkey” has the potential to be medically dangerous.
That was two years ago and hopefully you did not experience any unpleasant or medically dangerous side effects.
I would recommend having the discussion about whether you should take medications with a psychiatrist. He or she could assess your symptoms and help to determine if you should be taking medication, on what dose and for how long. It’s in your best interest to see a specialist about medications.
With regard to your parents, they were in all likelihood doing the best for you that they could think of. They did not fully understand attention deficit disorder (ADD) or how to treat it. They were not researchers in the field of ADD. They were not specialists. They took their child to get professional help. While they may have been wrong in light of newer thinking, they were following standard medical practice. If they were wrong, so were millions of other parents who tried to get their child the best standard of care. While your anger is understandable, it’s not helpful. They can’t change the past and neither can you.
In many ways, your situation is no different from that of many people. Very few people were raised by parents who did not make any mistakes. In fact, many people who enter counseling are attempting to correct the mistakes made by their parents. Fortunately, as an adult, you have the means to heal those early childhood wounds.
A low-dose medication may help you feel more focused. You may also want to consider psychotherapy for the purpose of learning behavioral approaches to focus your concentration. Please take care.