I would check out this link. It covers both ADD and ADHD. Read the symptoms for both of the links in green at the top of the page by clicking on them. The site is - http://www.help4adhd.org/en/about/what
If it feels possible that you have one or the other, then the next thing is to find a doctor. The link also has on the right side ways to do this. If you are enrolled in a college I could also talk with either your counselor or the medical staff. This is something that they are used to dealing with. If you do go in to see the doc, I would print out the list of symptoms that you relate to so you will have information to talk about.
Finally, feel free to ask if you need any more information. Best wishes.
You first need to confirm that you are having ADHD, and go through this link for knowing the symptoms:
And, if you think that you are also having some of these symptoms then you can consult with a mental health expert.