No, you would have at least had the symptoms as a child. I'm so sorry, and I can't say this with clinical certainty legally because I have never examined you, but it is likely that you were misdiagnosed.
The things that you are mentioning in your post, like high demand pressures, extra responsibility, daily demands, memories make me think that you should look at anxiety as being the culprit. You mention memories casually, but I'm wondering you are talking about memories that may be traumatic. PTSD is also often misdiagnosed as ADHD, and it is also an anxiety related disorder.
If you were diagnosed by someone who only looked at symptoms you are having but they didn't ask you about stress, trauma, depression, history of drug or alcohol abuse, age related memory concerns, current drug use, and a plethora of other issues, then they didn't do a thorough job. The days doctors don't have time to assess for all of these issues in one session and will pretty easily just go with ADHD. That might be why Wellbutrin isn't helping you much. You might try to get a full assessment, and treat anxiety, depression, and PTSD if they exist. The other thing you can do is talk to your doctor about non-stimulant ADHD meds. Vyvanse and Strattera are often prescribed to adult with ADHD, and prescribed off-label for adults who have focus and concentration issues that may be related to other issues. There are others also meds that are non-stimulant treatments that I am less familiar with.
You might google up queries like "can PTSD be misdiagnosed as ADHD", "can anxiety be misdiagnosed as ADHD" and so on, to kind of get a better picture of what I probably clumsily just laid out. Knowing what is causing your symptoms is the best way to determine the right meds (or peptides!) will work best for you🙂
By the way, you have over 400 posts, when do you get to change your name to Iamoldatthis🙂