If you want some validation, slip an x-rated magazine into a friends bag. I bet you will find it gets passed around to the whole group. If that happens would you feel less critical of yourself? And maybe come to terms with what you are doing isn't the worst thing in the world?

You will find a few years you will be bragging about sexual conquests to your friends. A right of passage I guess. Then you will mature a bit and find sex to be wonderful experience to add depth to a relationship. (or not and you will try to get as many notches on your utuility belt as you can).

The point is that sexuality isn't something to be ashamed of. A lot of people have sex, fanatasies, and just about everything you haven't thought of yet, someone else has already done and there is a name for it. To illustrate a point, there is a rather kinky thing called figging that you never knew existed and it is someones favorite thing to do.

Don't be so hard on yourself. Just learn to be comfortable in your own skin and don't be affraid of your own desires. Keep them in check. I'm not saying run naked down the halls of school, but having sexual urges and trying to figure out what exactly it is, is something that a lot of 17 years olds are doing right now.