[Serious] When have you seriously questioned your own sanity?

I had a psychotic break due to long-term stress, untreated depression and anixety a little more than a year ago. It had never happened to me before, and I was used to being very high strung. One night I was getting a ride from a friend back from a school club. He and I both had suicidal thoughts and self-harmed, and I was trying to get him to talk me about it so I could gauge how dangerous he was to himself. We sat in my driveway talking for a while, and I burst into tears because I was terrified he was going to kill himself and I couldn't stop that (this was a very emotionally taxing relationship, because he was ignoring all advice and not seeking help, unlike I was).

It was a typical I'm-sad-so-I'm-crying deal, but suddenly I felt like I lost all sense of composure. I started to hyperventilate, but I thought it was just a panic attack, so I sat up and focused on breathing. I've had many panic attacks in the past, and I'm pretty good at dealing with them, but the wave of panic that hit me was consuming. I started crying more, insisting that it "wasn't supposed to work like this" and basically curled into the fetal position. I couldn't remember who I was, where I was or what year it was. I kept pressing the button that activates the clock when a car is off and focusing on the numbers. To give credit, my friend kept repeating the date, location and my name, which helped. He called a friend who had helped me with attacks before and handed me his phone, and called my girlfriend on my phone. I ended up spouting gibberish at both of them and crying more, completely sure I was dying. I had no idea how, or why, but I was positive it was going to happen. There was no self-awareness. If something scared me, I made no attempt to rationalize it and became terrified instead. While being driven to my girlfriend's, I wasn't aware that I was in a car, just that I was moving fast and that could potentially be very dangerous to me. I actually had to be unbuckled and pulled out of the car by her mom and sat on the couch. Luckily, my girlfriend has many cats and they all promptly swarmed me, which eventually calmed me down.

It was incredibly frustrating losing control of my thought process and having to be dragged along with my emotions running wild. I lost all sense of self. It really stripped me of the control I felt I had over myself, and I was worried for a long time it would happen again. Fortunately, I'm doing a lot better now!

/r/AskReddit Thread