As someone with ADD, I find myself frequently becoming hyperfixated on things I want to do. Whether it's developing a website to solve a problem, or tending to my garden. I have a hell of a hard time discerning between behavior that is productive, and behaviors that will lead to my becoming upset. Sometimes, that hyperfixation can develop into focus, but other times it doesn't.
So what's the difference between the two? To me, the difference between hyperfixation and focus (or hyperfocus) is like this; if I can't seem to turn my focus from the thing I'm working on in a given moment, to another, that's hyperfixation. "Hyperfocus" would be when I'm completely in-tune with what I'm working on, but I'm not suffering from the one-track frame of mind that usually comes with fixation. Being attention-deficit, it can be really hard to actually achieve a level of focus that lends to productivity, so as a coping mechanism, I believe my brain has developed the tendency to become hyperfixated, so that it does not easily jump to another activity or subject. If I am forced to break from a given fixation, it can, a lot of times, lead to emotional responses. "You're distracting me!"- "I can't think!"- "UGH! Do I have to do that right now?"
In the moment, it can be really difficult to be introspective, especially when your brain is wired this way. I myself am still trying to find healthy ways to cope with this at age 27. The thing I've found that helps me the most is when I take walks around the neighborhood and breathing exercises, as cliché as it may be. This solution is two-fold: I am taking myself out of the environment that I became fixated in to begin with, putting myself outdoors where there is fresh air and sunlight, as well as allowing my mind to wander to other things. I allow my mind to think. I don't try coaching my thoughts to be on any one thing. I use my eyes to see what's around me and observe, letting my brain do the work. I find that my brain will still come back to the thing that I was fixated on, but at a less overwhelming scale.
This post wasn't really meant to be philosophical, but the takeaway ended up being that anyways. Here it is; you are a product of your environment. Maybe not your overall self, but you in this moment. If you're stressed, or can't focus, it may do some good to find a new place to be.