<human>: Can you give me the gist of the text in a nutshell?

I used to be enrolled in a teacher training course that would take up three years. The first two and a half year  went perfectly: always had good grades, worked hard, and came really close to graduation. 

The last six months, however, consisted only of teacher training - and that is where it went wrong. It's not that I wasn't good as a teacher or that I didn't put any effort in it. The problems were merely one of my teachers trying really hard to keep me from graduating, some administration problems, a principal forgetting he signed a training contract, medical issues - long story short, a bunch of problems that just came together and prevented me from graduating at the time I needed to.

It took two more years in which I attempted to start my training but never really could. By the time I started my training, I had got so emotionally and physically stressed that after two weeks of training, my stomach gave up and I started throwing  up blood and gall. My training was stopped, and because I had "officially" attempted three times (but in reality, only once but postponed due to administration rules), I couldn't continue my training/education and had to quit.

I am not taking another course, that will also take three years, in a completely different field.

My problem is, however, I "wasted" five years on a course of three years, without graduating and having a diploma. How do I mention this on my resume?
<bot>: I wasted five years on a course from which I didn't graduate - how do I justify the lost five years on a resume?