Dear,
Welcome to HCM
We understand your concerns
I went through your details. You are already 19. Childhood ADHD most probley would have cleared by the time you reach the age of 15 or so. Adolescent ADHD usually do not have the problem of notable hyperactivity. But lacks concentration.
Adult ADHD is also almost certainly lack concentration but without notable hyperactivity.
The symptoms you gave here do points towards ADHD but these cannot be taken into consideration fully. Mainly because there could be a bias in your symptom list. Once you think that you have ADHD, your version of symptom list will naturally have ADHD bias.
Therefore, I suggest not to overly worry about the present symptoms.
Consult a psychologist. Provide him all those symptoms you are facing. Please do not exaggerate or be biased towards ADHD. Let the psychologist assess your psychological disorder.
If you require more of my help in this aspect, please use this URL. http://goo.gl/aYW2pR. Make sure that you include every minute detail possible.
Hope this answers your query. Further clarifications are welcome.
Good luck. Happy New Year. Take care.