Good for you for asking questions first. :)
There are stats for transmission for hsv2.
Ghsv2 transmission, female to male, over the course of a year, assuming sex 2-3 times a week:
Only avoiding sex during an outbreak - 4-5%
Adding condoms OR daily suppression (Valtrex or acyclovir) - 2-3%
Adding condoms AND daily suppression - 1-2%
For comparison, if a woman is on the birth control pill, and takes it perfectly - same time every day, never missing a pill, etc - there is a 1% chance that she will get pregnant over the course of a year. If she takes it like most women take it - not at the same time, missing a pill, not using a back up method when she misses a pill or is on antibiotics, etc - it is only 91% effective, meaning there is a 9% chance she'll get pregnant over the course of a year. (https://www.plannedparenthood.org/learn/birth-control/birth-control-pill/how-effective-is-the-birth-control-pill)
If it's something you enjoy, you can still perform oral sex on her. Oral hsv2 is rare, and if you do get it (and again, it's RARE), it typically doesn't recur and it sheds rarely.
It's still your decision to make. I always say that herpes isn't a good enough reason to leave a good relationship, or stay in a bad one, but only you know if you are able to handle the possible risks. It's okay if you aren't, but if you aren't, let her know. It's only fair to both of you to be free to find a relationship that is comfortable for you.
Well it is possible for someone with genital herpes to asymptomatically shed, it is rare but statistics aren't really available for that. According to the cdc transmission rates amongst couples where one has hsv 2 and the other does not is between 5-10 percent per year. Condoms can reduce risk but not eliminate it completely so it is really your choice.