Look up ASMR. It does things like this. A lot of people have it. When someone plays with my hair I get a shiver too. On youtube if you search Asmr videos will pop up of people trying to trigger you...

Well about how long have you turned into this shy, unapproachable person? If you're still in school, which you probably are, have you changed teachers? Is it a certain class you're afraid to speak...

Well, when I get really mad, or I am about to do something mean, I feel dizzy. Like other people said, its your adrenaline that gets pumped up really high and you feel much power at the same time. ...