I just found out this week that my boyfriend has genital herpes he knows that he has been the only person that i have been with, so now does that mean i will definately get this

best advice is to do your best to protect yourself. You may or may not get it. I hate to break the news, but you probably have been exposed to the virus. Unfortunately Dr's don't seem to know a lot about the virus except it is life long. If you do show signs of it, it is not the end of the world. If you have a great guy, keep him. This does not define who he is or how your life together could potentially be in the long term.