You need to check with your doctor, tell the guy and take the medicines, also you should let others future partners know. Don't be so scared, you'll be fine, but do more careful.
Try this website: http://www.cdc.gov/std/herpes/stdfact-herpes.htm
It may be able to give you some info on what to do now, besides seeing your doctor and alerting this guy so that he doesn't spread it further.
Get Matched With a Therapist If you would like real online counseling from trained, Licensed, and Certified Professionals, visit our Therapists section to take a questionnaire and be matched with a counselor that's right for you.