It's never too late to press charges. Not to be harsh, but do you want these people to do what they did to you to another woman? What if they did that to another woman and she ended up dead? When you press charges, tell the police that these people threatened you and your family if you told anyone. Stop giving these people so much power over you!
Many, many, many women who have been raped have pressed charges. When all is said and done, these women say it has helped them heal. I'm really surprised that your counselors haven't counseled you to do so.
Are you in the US? If so, call the Rape Crisis Hotline 1-800-656-HOPE. The person on the other end of the line can advise you on how to press charges.
The rapes were not your fault---always remember that. So don't take it wrong when I say this --- always be aware of your surroundings. If you go to parties, make sure you go with a friend and that you know the people in attendance. If someone offers to walk you home and you don't know that person, decline the offer. If you know the man who walks you home and he wants to stop off at his place first, say no. While I understand that taking all the proper precautions is never a guarantee of something bad happening, it certainly reduces the chances. Good luck and get going!