How to deal with past unintentional and unpunished plagiarism? I am currently a master’s student and I cautiously and properly cite in my essays and works as per Harvard’s guidelines. However, I only learned how to properly cite just this year which made me go back and look at my BBAs graduation projects (I have two licenses) and, frankly, they are horrible when it comes to referencing!

To make a long story short, these projects are made up of ‘copy-and-paste’ chunks from online websites, Wikipedia pages and some books, all without putting quotation marks, however still referenced at the end with (some of them) a poor style. Back then, I never thought about it and was like, yeah I am just referencing the ideas. I was not aware of direct quoting, quotation marks (save for small definitions), proper paraphrasing and a proper style of citation. It is important to note that it was totally unintentional to plagiarize, just out of ignorance.

What to do now? Frankly, I feel so guilty about it since I am an ethical person. Although both projects were positively accepted (one of them is a technical one; a website, so the report was only to define some concepts), I, first and foremost, do blame myself for my ignorance and carelessness, however I also blame my instructors for not throwing the projects at my face and telling me to go home and correct everything! What can I do now? No instructor told me anything about it and this was four to five years ago. However and ethically, I am suffering because of this, I feel like I don’t deserve to be a graduate student (unlike what my current instructors think as I am seen as an excellent student at this part of my life and my current master’s grades are excellent and I even cite during exams!) and should just drop out and not use my bachelor degrees in life, yes I feel that way. Why to bother pursuing an MBA and even a PhD if my BBAs projects were built on academic dishonesty (even if unintentional)?

I am so glad that I learned how to properly cite this year just before my master’s thesis so that I can produce a well-written one, but again, I am not motivated due to the aforementioned reasons.
First, it is unreasonable to blame your instructors.  For what reason?  If they had done something years ago, you wouldn't feel bad now?  Probably it was not obvious to them that you had plagiarized.  (Plagiarism can be more obvious or less obvious, depending on many factors.)

Second, people make mistakes in life, and not all mistakes are fixable.  You just have to do your best to be honest and correct now and in the future.  You might consider contacting your old professors to let them know what you did, and that you now realize it's plagiarism and that you are sorry.  If you need to do this to feel you are "deserving" of your situation, you could also redo your projects and send them to your old professors, but this is not ethically necessary.  Who among us deserves the fortunes granted us?  Not I.  I can only appreciate them.