Symptoms Like Mine?

Hi Everyone. I've had several negative EEGs and so it's not clear I have epilepsy. I was just wondering if anyone has episodes like mine, because I've never seen any description that matches what I feel. The "attacks" come on all of a sudden, with no warning. It feels like a pulsing in the back left of my head at first (but it doesn't hurt), and my heart rate goes up a lot. The first time I had one I thought maybe it was a heart problem or something like that. Then the left side of my body gets hot and cold, alternatively, and I get goosebumps - again just on the left side. Meanwhile, I don't know how to describe how I"m feeling in my head, but it's kind of an unreality - things seem to sound different even though I know they don't. These symptoms kind of repeat themselves for up to 45 minutes, though usually it's more like 20. And I'm usually wiped out after one of these episodes, but still pretty functional. As for frequency: they seem to come in cycles. A couple of days ago I was having one or more every day for a couple of weeks, but earlier this year I went a couple of months without a single one. Anyhow, any help would be very much appreciated - it would just be not quite so terrifying to hear of someone else who kind of understands what I'm experiencing.