What are These Sensations?

I get the freakiest sensations inside my head, like my brain feels "startled" over and over again in the space of a few seconds or minutes. It builds up like a little pressure wave and then releases. "Startled" is the only word I can find to describe this sensation. I feel like my head is falling forward when it's not actually moving, then the startle thing happens and I jerk slightly. This can go on for hours, then I start oozing tears. I'm not actually crying or sad, just quietly oozing away. Also, I get these psycho emotional waves that make no sense. I get overwhelmingly oh-so-happy, then seconds later, I feel such rage I start looking for something small and fluffy to dismember. I know that all of this scares my kids and husband and that is the most horrible feeling of all. I want to just chain myself up in the basement until the hair on my knuckles retracts. The only warning I get is sometimes I smell imaginary stuff or the edges of things get glowy or I get hyper-sensitive to noise and light; otherwise nothing. Does anyone else out there have the weird brain feelings? They aren't described anywhere. I had a very un-interesting EEG a few years ago, so I don't even know if I really have epilepsy; it could be brain squirrels for all the docs can tell me.