I'm worried i have testicular cancer, i have researched and found that varicocele is a possibility, it is in the vein of my right testicle and aches?

Unlikely: Testicular cancer would produce a swelling of your testes as the first sign . If you have any suspect mass/swelling then you should go show it to your doctor or seek consultation with a urologist(who can also check you for varicocele).

17 is in the peak: Age for testis tumors. You need to be examined by a doctor, perhaps a urologist, and usually an ultrasound is the first step after exam. Hydrocoels and varicocoels can be distinguised clinically or with u/s. Epidydimitis is another prospect. If you cannot get help from mom or dad, go to an er, urgent care center, or look up a urologist to see if they will see you. I would.