I cant focus on school any more

i have never seen a psychiatrist, but recently i feel like to talk to someone , unfortunately ,i cant tell it t anyone .
you see am 17 , and i come from a very religious family , i was always the good girl ,good manners , great grades and everything , but since we moved to Texas i saw people my age doing all kinds of things.
something in me just wanted to try the things. so i did ..i started making out with this guy that i thought was cute , and things kind of got awkward since he is a family friend and i see him alot but i liked him because couldn't have him . from making out to second base to oral sex (just on him ) .. my first .. i didn't hate but i love it either ..
am a junior in high school , my parents have high expectations for me ..really high i don't want to mess up my future for a good kisser .. but then again i really cant stop thinking about him .. how can i go back to my old self nerdy old me ?
i want to make it to Cornell university and then medical school .. i need help

Your situation reminds me of the saying, "How can I go back to the farm, now that I've seen Paree (Paris)?"

I know many guys these days expect some sort of sex from a girlfriend. So, some girls go the oral sex route. However, if you really feel uncomfortable with that, then you don't have to do it. Frankly, I think a decent guy should be happy with first base. The danger comes in, I think, from trying to date too much and too heavily too early. Are you planning on marrying anybody anytime soon? Then why the big push to get so involved?

You say you can't stop thinking about this guy. I suppose you could just flat out tell him that you care for him, but just don't feel right about any sexual activity below the waist. If he can't deal with that, then he's not the right guy for you.

You say you want to go to Cornell? You will certainly have the opportunity to meet guys there or any other university you go to. You have plenty of time. Meanwhile, if you are planning on a school like Cornell and medical school, then you know your grades are very important. It's your life and just because you feel (emotionally) some attraction toward a guy now at your age shouldn't mean you should throw your life away for that. Think of your long-term goals. I was a nerd and I'm proud of it. I got a Ph.D. from Duke, and I met a wonderful guy. (I actually saved myself for him--and he did for his wife, too. That means a lot to me.) We have been married for many years and have two remarkable young-adult children.

Try not to worry about what all these other kids are doing. The operative word is "kids." Okay? It CAN be done, and I know you are able to be smart enough to hold off until a greater guy comes along, who won't possibly interfere with the great goals you have set for yourself!