ADHD? what do you think?!

I started my first year of college in the fall and am now starting my second semester, in high school I would day dream quite frequently but still be able to get by with C's and B's in my classes because the material was very easy to understand and comprehend. Last semester and my first in college i started noticing there was something wrong with me I would get homework assignments and projects assignments and know when they were do and tell myself to do it before that time frame but i would always have trouble keeping my attention to the assignment i easily get distracted by the littlest things whether it be the TV, computer, cell phone, or another person in the room and than i get aggravated and just don't even start on the assignments. I tried putting all the electronics away and just studying to myself but as i am reading the material my mind is doing something else, im reading but thinking about something completely irrelevant or i would read the material and not comprehend anything i just read as if it just went in one year and out the other, many times I've had to reread the material and my brain and body becomes very aggravated because of this and i go into stress mode and procrastination mode. Also even when i am sitting quietly or alone i have noticed my legs or hand are always moving in one way or another i don't know if this is a sign of anything but it wasn't like this before. I fail to finish many assignments and procrastinate most till the very last minute because my brain is not wanting to do the work because i get so aggravated if that makes sense, and it also seems like my moods constantly up and down and is interfering my relationships with the daily people i am around, because i get so aggravated for not being able to function and do my work that i get hot tempered and say things and act like i usually don't. Since i started noticing these symptoms i have started smoking cigarettes on a regular basis and drinking alcohol excessively when i get stressed or feel down because i am not able to complete my assignments and then just go into a careless mode. I work a full time job and having to deal with all of those issues really affects my work too. I have read a lot about ADHD and all the symptoms i feel as if i can connect too them but i am just wanting to know if it is ADHD im experiencing or is it something else, i took addarell for the first time today and studied before my tests without any problems it actually motivated me to keep studying, and i had no problem doing it i ended up scoring better on the two tests i did today than any other ones i have taken both of these semesters that i have been in college for . I did not experience that can of motivation before, so i am wanting to know do i have ADHD or something else?