I am in a similar position. I’m a final year law student and working in a professional legal environment.
I have been diagnosed with ADHD a few months ago and finally went to see an education psychologist last week. She told me that I need to find a way to center myself in order to re-align with the true me. My response was that I have no idea who that is.
As far as “not working hard enough” I’ve been called lazy so many times in my life that the word has gotten an extremely negative meaning. I got a new manager last year who point blank told me that she doesn’t think there are other issues, that I have a reputation for being lazy and that she thinks that is all that is wrong because the amount of work that I do does not equate to the number of hours that I say I work. I must state that I have also been diagnosed with dyslexia and I read significantly slower than the average person. In the legal field, you will know how problematic that is.
The good thing is that it forced me to get diagnosed but now I am so intent on proving that I am not lazy that I work late instead of exercising and I work most of the time over weekends as well. If I’m not working I’m studying.
I don’t know when the guilt will go away, but I do hope you find a way to deal with it that works for you.