Thank you for getting so brave and opening up about these horrific events. Although you may or may not have been raped, sexual assault can be traumatic as well. Either way, whatever this person (or these people) did to you must make you feel awful and disgusting inside, and not only that, but panicky and unsafe. While the emotional and mental pain doesn't ever go away completely, it will get better with time. Many, many girls have experienced sexual assualt, abuse, harrassment, etc. and it's a sad fact. But on the flip side, that means there will be many, many girls you can talk to about this who can relate and may be able to help and advise you.
You can even contact RAINN through their online live chat, by phone or e-mail. I have done the live chat and the results were pretty good. I went twice; the first time, I got someone who was...meh but the second time, the person was very helpful. If you feel you need further help or are having difficulty with your emotions (which you very well might), try to get some face-to-face counseling. You can either talk to your school counselor or try to get one outside of school. The next time you go to your regular doctor, tell her/him that you would like counseling and give her (or him) the reason. Then, she or he will give you a referral (you can't usually get a specialist without a doctor's referral, so I assume therpy works the same way; that's how I got it).
I do advise you to at least tell your parents, though. They should be involved in your life and know if you're having any hard times. It's also good to get comfortable with the fact that it happened by talking about it (not a lot of people, just trusted friends, family members or counselors) so it's easier to deal with.
As for not dating because of that, don't be ashamed of it. It's no harm not to date and it can make your whole life less complicated (just take a look at the Relationships forum). Anyway, a lot of teens are too quick to trust their dating partners and date rape does happen. But that doesn't mean all guys will do that to you. If you are patient, the right person will come into your life. I don't know if you're religious or not, but God brings us the person we are meant for when we are ready. The same goes for if you're not religious. Usually, it comes when you're not looking. Don't sweat it now. Enjoy your youth despite what's happened and go after the things you want without worrying about long-distance, cheating, intimacy and every other problem that comes with teenage relationships. It'll come when it's meant to.
God bless you! I pray that He will heal and resolve your confusion and hurt and that He will allow you to trust again