I actually stumbled across this question while searching this site for an answer to my problem. I made an account so I could answer you since your situation sounds tough. I have ADHD and have since I was 7, but I am also a bit younger than you and am in high school. Please don’t let that take away from what I have to say though because I speak from experience.
Before I was diagnosed with ADHD, I couldn’t focus and my grades were low. I would talk nonstop and interrupt like crazy. Even now I am still talkative and interrupt sometimes. I take medication for it now and without the medication can’t focus and get overwhelmed.
The fact you have two degrees is a feat I don’t think I would be able to achieve if I didn’t take my meds. Also according to my doctor some people age out of needing medication for ADHD. I don’t know what school was like for you so I can’t really say how bad your struggle was with concentration.
What I mention next is just something that I am sharing. I am not saying that you suffer from this though.
When I found your question I was actually looking to see how depression symptoms and ADHD symptoms are similar. This is because I was trying o link how I feel now to ADHD, but this isn’t about me. According to several things I have read ADHD and Depression can look very similar. They share symptoms like lack of concentration and forgetfulness. Not saying that you are depressed though. I don’t want to label what ever you are dealing with because like I said I am not a professional. But the article I was reading also mention that some adults that didn’t have ADHD diagnosed when they were younger have depression as an adult.
The link to that article is https://www.additudemag.com/adhd-and-depression-symptoms-treatment/
I don’t know the answer to what you are dealing with, but I figured since I have ADHD it could be of some help. If you have any questions just reply back and ask I guess. If this wasn’t helpful I am sorry to have wasted your time.