If i have hsv2 and me and my boyfriend have unprotected sex while i'm having a outbreak is it a 100% definite guaranteed that he will get it?

No: While transmission is more likely during outbreaks, most transmissions occur when there are no symptoms or outbreaks at all. That is a major reason why 1/3 of women test positive for type 2 genital herpes. Virus is shed even without outbreaks - people are contagious and are not aware that they are infecting a partner. Btw, consider having him get a blood test - he very well may already be positive.