I experienced many of the same feelings a person might have if someone they loved were to suddenly pass away. And the situation was made even more painful by the fact that when I visited her in hospital she didn't even recognise me and wasn't able to take any comfort from my presence.
I was haunted by the fear that I would go crazy, too. But I could not talk to my parents, because they were too anxious and depressed themselves to listen.
I was painfully aware of the cruel stigma attached to mental illness. This made me feel that I could not talk to my friends about what had happened, or about the cyclone of emotions it was stirring up in me, for fear of being snubbed. At age 13, fitting in is more than a desire - it is a necessity.
Naturally, all of this gravely affected my performance at school. My grades fell because I was so overwhelmed and distracted that I had difficulty concentrating. I was burdened by my terrible secret. I felt horribly isolated. And my social life dwindled, as a result, right when I needed more support than ever.
If only I had been able to talk to even one teacher, my pain would have been significantly eased. But I could not, because I felt I had to keep my secret from everyone. And how could my teachers help me through it, if I was not even willing to let them know what was going on?
As educators, the first step towards being able to help a student who is experiencing a similar crisis, is to be let in on the secret. If you are fortunate enough to be trusted by a child living through this painful situation, I expect that just the simple act of listening to them will probably go a long way towards helping them to deal with what is happening.
And perhaps you could recommend that they try keeping a journal. This certainly helped me to survive those harrowing times. Pouring out my feelings onto those clean, white pages every night gave me an enormous sense of relief.
But the sad truth is that your student will more than likely choose to suffer in silence, because in the 35 years since the onset of my sister's mental illness, there has been pitifully little progress in obliterating the stigma against the victims of this disease and their families. And since one out of five people is stricken with a mental illness in any given year, vast numbers of people are affected by this.
So, I think the larger issue of raising consciousness needs to be addressed. Do we wait until we somehow hear that a student has a family member going through this, and then direct our attention towards making it easier for that child? Or do we begin to think about creating a curriculum that focuses on raising consciousness about mental illness?
Perhaps we could start by exploring the physical causes for mental illness, so that the distressingly common myths that mental illness is a choice, or a sign of weakness, or all just a "big act," can be dispelled.
Then we could delve into how mental illness has been portrayed in literature, so that students who are not living through this terrifying experience, can gain a deeper understanding of what it feels like to lose someone to the disease, or even to succumb to it themselves.
Books like Girl Interrupted, The Bell Jar, and I Never Promised You a Rose Garden are moving depictions of what the descent into madness actually feels like. And books such as When She Was Good, Memories of Summer, and my own book, Stop Pretending, explore the horror of what it feels like when someone you love is stricken with mental illness.
Reading and discussing these books would go a long way towards helping students to a deeper understanding of this disease and all its repercussions. It would also help students to be more sympathetic towards the victims of mental illness.
My sister was diagnosed as a manic depressive, but with the help of medication, she's been able to lead a productive and satisfying life. She married, earned a masters degree in library science and was a public librarian for over 20 years. When I told her that Stop Pretending was going to be published, she was delighted. She said: "A book like this could be used to open up discussions about mental illness in schools."
Sonya Sones is author of 'Stop Pretending' and a Hollywood film editor