I've only ever OD'd on MDMA. Which was terrifying for the short time it lasted. I'd accidentally taken my partners bomb shortly after taking my own, effectively doubling my dose and then some. Ended up being around 0.35g in the space of 10 mins, which is well over 3x my usual dose. I got extremely nauseous and started sweating profusely. Ran to the bathroom to vomit, but I couldn't think straight. I was so unbelievably hot and my skin was bright red. I wasn't sure what to do as I couldn't stand up or speak, so I dragged a towel into the bath from the towel rail and just about managed to turn the cold tap on. Then my partner walks in and sees me sweating on the floor, skin glowing red, failing to drag a soaking towel out the bath. She touched my back and realised how hot I was, so chucked the towel on me and fed me some water. Within less than a minute I was fine again. But I pretty sure I would have died if she hadn't come in when she did. My vision was starting to go white and I was loosing the use of my arms, I would have died, I'm sure of it. And that was the last time I took and stimulants.