How could I explain a 2 year gap in obtaining a degree due to dropping out and then returning?
Only completion matters
As a hiring manager, I don't care if it took you 2 years or 10 years to get a degree, to me your degree is effectively a bullet point. (an important one, but still just a note)
Why I care about the degree, but not how long
We've all heard the horror stories of professors who unjustly failed students, degrees getting dropped without notice, change in degree requirements, etc or even just working through your degree to come out debt free. All of this cause degrees to go longer than expected, and are so common that these days getting a 4 year degree in 4 years is becoming uncommon.
That said, having that degree tells me you put up with all the bureaucracy and struggles a college student deals with, plus you learned at least a reasonable level of competency in the subject matter. Whether you can apply it remains unseen, but you at least have the well rounded knowledge pool and ability to learn that is required to earn your degree.
List only completion dates
Treat your degree as if it were the single most valuable certification you've ever earned. It needs to be in it's own little spot that says "hey I know things!" but isn't a life story, because frankly as a hiring manager I don't care.
The most common format I see is:
- Name of Degree Earned, School Degree was Earned at, Year Earned
Avoid listing start times, time taken off, degrees you didn't
earn, etc. If you are still a student or pursuing post grad you can add a line saying what degree you're pursuing, where you're pursuing, and an ETA, but whether that matters to the hiring manager depends on the company and individual looking over your CV.
What if they ask about it?
Be honest, likely the question won't be "did you take time off your degree?" or "how long did it take you to get your degree?" instead you'll likely get "What was a problem you ran into getting your degree and how did you handle it?" or similar.
As a hiring manager, the only interest I normally have in your backstory is to figure out how you think. Will you be reliable, do you see things through. etc.
When a question like that is posed, be honest but answer the question without going into completely unrelated stuff. (One, because you shouldn't be telling me why not to hire you, and two I probably don't care)
So for your example "Well I had a great deal of stress during school, at the time I felt school wasn't necessary and decided to just jump right into my career... that didn't work out so well, it set me back quite a bit, but I went back got my degree"
To me this is a good answer for such a question, you made a choice under duress, it didn't work out, so you took corrective action. Pretty much the sort if thing I want to hear.