You almost certainly have it. Let me give you some advise from someone who was diagnosed with A.D.D. from the time when it was first discovered. (For what is it worth -- I can tell you are HIGHLY intelligent which is normal for us.)
1 - Most importantly -- Do not take advise from these discussions. Just look around at some of the these inflated opinion posts; which might be funny if they were not so sad. You do not need opinions from self-proclaimed arm-chair experts who know nothing about it. Get the facts. A.D.D. has been studied and elaborately documented for years. The real information about it awaits you to simply retrieve it.
2 - Beware of the medications, and do not blindly trust the doctors in regards to them. Read about them yourself and protect yourself by being an educated patient. For instance, anti-depressants are neither safe nor effective in long term use, although the establishment has been unethically pushing them on us for years (cough... kick-backs). Ritalin is by far STILL the safest (ie. "as safe as aspirin"), and often the most effective medication. Again, become an educated patient.
3 - Carefully monitor what you eat. Try to eat foods void of anything artificial, including colors, favors, and etc. A.D.D. people are extremely sensitive to toxins and allergies, and these include the chemically engineered garbage ... I mean "food"... that most people eat regularly. If you pay attention, you will also notice mood reactions to foods at many fast-food restaurants such as McDonald's and KFC -- and possibly worse than just mood swings.
4 - For concentration, use something to provide just a bit of background noise ("white noise"). It is like shooting a gun with the sight bent -- you have to aim slightly off to hit the target. If you try too hard to concentrate, you will fail.
5 - Feel good about yourself. While in some ways A.D.D. can be crippling, at the same time, it will give you abilities that other people lack. For instance, you should develop the ability to mult-task in a way that vastly surpasses your peers, and your passions will give you a relentless energy in the pursuits you enjoy.
6 - If you ever have trouble sleeping, then drink some coffee! It is funny and true -- stimulants effect us in an opposite manner than is normal. I drink coffee to relax and focus better on my work. Of course, if you overdo it, then it will begin acting as a stimulant. This has been a problem with medications in fact -- giving too much can make the symptoms worse.