I can imagine that how embarrased u might have felt.....what happened by u is commonly seen in youths and is absolutely normal.
First thing u have to explain urself that during youth age there is going to be sexual urge and to control it and express it in socially acceptable manner is normal resolution of passing youth age.Masturbation
is found to be scientifically safest way to outlet ur sexual urge .
So dont feel awkward that u done something abnormal (though checking private things of others is not a good manner and consequences of same u experienced so avoid it in future)
Still if u feeling disturbed pls consult to ur nearest Psychiatrist