What Causes Unusual Electrifying Sensation And Pain Inside Mouth After Brushing?

I have a weird Electrical/vacuum type sensation in my upper teeth after brushing or using my mouthwash not sure which is causing it. It is really painful when it first happens, and then the pain slowly diminishes after 10 minutes. Only to return after brushing again. What's going on? And how can I avoid this until I can afford to get to a dentist.