"Insecurity attacks" -- how to stop and prevent them from happening?

This is actually very common. The thing you are having is actually called a panic attack, it sounds like you could even have some anxiety. The only way to stop this or have these attacks slow down a little is to think positive or trick yourself into thinking something good. Everything is really just mind over matter. If you think something in your head hard enough you will soon believe it even if it isn't real, so stop saying your insecure (even if you are) and start saying something positive. You could also see a therapist and they could help you with this problem more.