ADHD....more HD if so...or just impatient?

When I am at work, any job I have ever had, I need to be busy. If we have downtown of any kind....a few minutes fine but 2-3 hours literally and usually at the end of the day like at my current job...I get anxious which then becomes frustration and can turn to anger especially if given menial tasks to just pass the time that are not related to my actual job. I don't casually socialize well or look busy well but when there is work to be done, I am on it. I have walked off the job from this a few times and basically said if you can't keep me busy then my position is not necessary. I'm trying to manage this by just staying busy looking at news on the computer and what not but now we have received notice that only on breaks can we access non-work related webpages. They are fine with people congregating and just talking though for an hour or so when we have this downtown.

Anyone else or just a random ADHD symptom I have. Any coping techniques recommended?