It is not fair, but life is not fair. Taking the initiative to overcome these obstacles will make you a stronger person than those who glide through life more easily. Honestly, I learned all the following study and organization tips from non-adhd friends and from school.

In school it is useful to have separate notebooks, folders, and colors assigned to each subject. Keep a planner of assignments, due dates, test dates, and update it as frequently as possible. Also keep a monthly wall calendar with deadlines and special days noted. It is tricky to stay organized, I am still learning new ways to stay on top of my life and keeping it less cluttered.

Regarding studying, you have to learn new tricks to focus. Some people listen to music, I need silence. I like a quiet library with no one around and no distractions like cell phones or computers. If I get bored I switch from reading text books to reading or writing flashcards Or switch subjects. Writing or typing an outline is another way to focus while studying a text book or long notes. Some people highlight textbooks to pay more attention. Try reading out loud as long as you are not distracting anyone. There are several tricks to be more focused.

Cheer up, once you learn good habits, organization and focusing is easier to handle!!!

I am currently in college. I use a 5-subject notebook with pockets separating each subject, so it is all in one place but not all jumbled together. Otherwise I have to make an extra effort to remember to bring all the right notebooks and folders, and that is just problematic for me.

I also use Google calendar and I have it send me reminders for events/appointments. For me it works to get reminders 2 days ahead of time and then leave them in my inbox unread so I will actually see them multiple times.

I also try to keep simple to do lists in the back of my notebook, since it is with me daily, and I have it for about a week at a time, so I can plan a bit ahead and also remember what is coming up. I do have a big calendar on a whiteboard at home that I write major things on, like test dates and appointments.

Keeping on top of all this does not always happen, but I keep working at it. It makes a huge difference when it is actually working.

I agree with the suggestions from the other two replies.I can't study unless I am alone in complete quiet. And sometimes it takes me more time than it does other people to tear myself away from everything else in the environment so I can think about studying. Additionally, though,if I was under the care of a physician for ADHD and had the formal diagnosis I would go straight to Student Services on your campus and formally request an accomodation for your disability.It is state and federal law and could be a violation of your civil rights if they don't do it.Most colleges and universities are able to test their own students with learning disorders to determine the accomodation needed.Some of us with ADHD have another learning disorder or two that we may not have been aware of until the testing is done.
Usually the accomodations that the tester will recommend for ADHD are things like being allowed a little extra time to complete things like math problems, being allowed to take tests in a separate,quiet room, ect.
OMG, I hope that wasn't a faculty member who made that derogatory comment.That is verbal abuse.If they are aware of your disability, you would have a right to file a formal grievance against them for harassing you about a disability, or request to be placed with a different instructor.That is the equivalant of them telling a wheelchair-bound student that if they would move across the campus faster they would be more successful.
If a family member said it I hope you won't continue to tolerate verbal abuse from them either.