A few tips. Not solutions, but touchpoints:
Assess your health. An injury left me with a lot of nasal congestion and discomfort. This severely limited my focus compared to prior. Allergies, etc. can be similar. Regarding this, I've become increasingly convinced that many psychological and psychiatric diagnoses are diagnoses of symptoms stemming from underlying physical problems. And our (U.S., at least) fractured medical system means that the underlying causes can easily go undiagnosed especially with regard to these cognitive impacts. (The poster child for this might be sleep apnea; at least it now finally has mainstream recognition.)
Environmental sensitivity. I have an extremely difficult time tuning out surrounding activity -- particularly human activity. Conversations, people fluttering about in my peripheral vision, etc., destroy my concentration. Assess your workspace(s), the variations in their activity levels, and any corresponding variations in your productivity.
With peace and quiet, after an hour or two I could (sometimes still can) achieve what at least in the AD(H)D domain is sometimes termed "hyperfocus". Once "in the zone", I could really concentrate, and I could then achieve not just more volume of work in a given amount of time, but also a depth of insight and analysis that others often just couldn't achieve.
If it's noisy and disruptive, though: Fergetaboutit. Sometimes, once in the zone my focus would become so intense that surrounding disruptions would simply fade out of my awareness. Not always, though, and it is something I could not / cannot control.
I should add that I do not have difficulty interacting with people. Actually, most people seem to rather like working with me. Being around them is just fine, when we actually are working together. But when I need to do something they are not an active part of, their presence can be very distracting.
Medications. Turns out, I'm rather sensitive to these (I'm just a sensitive guy, I guess; I suppose that explains my meager dating life ;-). Many psychiatrists have no concept of this. St John's Wort helped me some (though not necessarily for ADD symptoms; in fact, I sometimes wonder whether it makes them a tad worse for me). Zoloft and its many siblings and cousins made me much, much worse. More recently, I've run across some descriptions of what is called "serotonin poisoning" -- too much serotonin. My symptoms on typical/standard doses of e.g. SSRI's fit this to a T; yet, despite describing these symptoms to the prescribing psychiatrist (to be clear, not just a physician), this condition was never even raised by them as a possibility.
Eventually, I learned of a psychologist with a psychiatrist wife, whose profile seemed rather similar to mine. And he had found that one rather low dose of Adderall in the morning was all he needed. I tried that -- after finally finding a psychiatrist who was willing to consider its use concurrent with St. John's Wort -- and, after finding even 5 mg too much, settled on 2.5 mg. My difference being that I'll typically take 2 doses 6 hours apart (the effective life of many drug doses, for me).
I'm not saying you fit this profile. But there are elements that may be of use in considering. And be aware that, at least in my experience, there are a lot of "professionals" out there who won't have the first idea about really helping you.
That doesn't mean you shouldn't try. But keep your sense of self, self-respect, and the old bullshit meter set to "High".
One final thing regarding medications. About... 7 or 8 years ago, psychiatrists started pushing low doses of anti-psychotics for (initially, at least) off-label treatment for a broad range of other conditions, including AD(H)D. Well, it turns out that at least one factor in that was a push by drug companies to develop new markets for these drugs. IIRC, in particular Johnson & Johnson ended up settling with one or another government agency for an amount in the many millions of dollars, for what was determined to be mis-represention and violation of regulations in this regard.
If someone starts trying to sell you on the idea of Risperdal or one of its many siblings and cousins, I'd consider very carefully and insist on a very detailed argument for this, before proceeding. The lower doses are supposedly safer, but these classes of drugs are -- in my limited layman's understanding -- not something to take lightly, as it were.
Actually, one more thing, I guess, about medications: For Adderall, at least, there apparently are differences between the brand drug and generics, and there are -- in my anecdotal experience -- definitely differences between the different generics. I experienced the latter unexpectedly when my pharmacy changed suppliers in their stocking of a generic equivalent. It was not a pleasant experience.
As I say, it was for me completely unexpected. Only after having the initial experience did I google around and learn that I was not alone in it.
A final postscript: Heavy, daily exercise also helped me. Unfortunately, a bad leg injury subsequently quite severely limited this for me. But I'd recommend it, if and as you can.