My supervisor seemed understanding, telling me I was 'one of the strongest students' he'd taught, and not to worry as sometimes life gets in the way, and I should take a study break if necessary.
Taking a break seems a great idea, I think your supervisor said good things here.
I therefore took a year off, and came off the medication.
It is great to know that you got better and came off the medication! Congratulations!
I did not tell the supervisor in advance that I was going to be on break for a year, just that I was taking a break as he advised. I did not know in advance how long a break would last.
No one could know how long the break would last. Knowing that is simply impossible. So don't worry about it.
Neither was I in communication during this time. When I was depressed, nothing else mattered.
Agreed. Again, don't worry about it. The fact that other things matter now is another evidence that you are better :)
Just before I was considering returning, I sent an email to the supervisor just asking about what we should do next.
Good! However, just keep in mind that in written communication it is hard to express emotions, tone, and such. So this form of communication has a few drawbacks and can lead to misunderstandings. But overall, it is fine.
His reply was to say how terrible my performance had been so far [...]
He certainly could have chosen better words. But let's make an effort to put emotions aside for a moment. It is true that you made no meaningful progress in the last two years. But you, more than anyone, already knew that. And more importantly, it is utterly completely extremely okay that you made no meaningful progress. You were tremendously sick after all! Who can make any progress being extremely sick?
[...] and that he strongly advises I should quit.
Hmmm... I don't know what is the right thing to do (no one does), but I know that if your advisor no longer wants to advise you, then he should stop being your advisor, it's a win for both of you. But please note that leaving an advisor is just leaving an advisor. You can find a new advisor, why not? People change advisors. It won't be the first time someone changes advisors.
I felt devastated to say the least.
Good... Feeling devastated over devastating things is what should happen. If you didn't feel devastated I would be worried. It means you're human.
Is he right after all [...]
No one will ever know whether or not he is right. The good news is that it doesn't matter. What matters is simply what you will decide to do.
and should I really quit?
Hmmm... As I said earlier, I think it would probably be good for you to look for a different advisor, since your history with this advisor got messy. People change advisors. It's normal. No need to make a fuss about it, things just turned out in a way that seemed that you two won't work very well anymore.
I thought he was so supportive to begin with and actually suggested the break.
From what you said, apparently he was indeed! And it's great that you accepted the suggestion, and got better! You getting better is the most important thing in this story.
Now, one year has passed and your supervisor said something different... Well, advisors are humans too, right? One year ago he thought you should take a break, now he thinks something else! People change their minds. And this may be for one million different reasons. Thankfully the reason doesn't matter.
Or is the blunt truth correct?
I am not sure what you mean by "the blunt truth"... You seem to be implying something... And although this is written communication, I am going to guess you are saying this in a pessimistic tone. Perhaps implying that you're not worthy of a PhD? Perhaps implying that you're not good enough? Or something like that?
Stop it right there. These are astronomically absurd conclusions. Firstly, there is no "the" here. Using "the" makes it look like everything boils down to one little fact. Life is immensely more complex than that. Secondly, the words of your advisor may have been blunt, but there is no "truth" and especially no "blunt truth" anywhere here.
Whenever you see yourself taking drastic conclusions about something, take a step back!
Doing a PhD was my dream and now it is shattered.
No it's not shattered.
You just took a sudden drastic conclusion again.
To me, it looks like doing a PhD is your dream. Where did that past tense come from? If it wasn't your dream, would you be here asking this question? The fact that you got devastated after reading that email is yet another evidence. We humans only get devastated about things that really matter to us.
An advisor saying (although with a bad choice of words) that you should no longer be advised by him, because you made little to no progress in two years (which is obvious because you are a human and you were super sick, as I said):
- Simply becomes someone that should no longer be your advisor;
- And is astronomically far from "shattering a dream".
You will be fine!!