No, you will not get Herpes Simplex Virus 1 (HSV1) back from your girlfriend. Once you have had your first outbreak of herpes, your immune system will make antibodies to your type of herpes. This can’t get rid of the virus, but it will protect you from picking up that type anywhere else on your body. You already has HSV1, and it sounds like your first outbreak was long ago, so you will not get HSV1 anywhere other than the original site where you first got it.
You may or may not ever have a breakout from your HSV1, but it will not be caused by having sex with your girlfriend. It is still possible to get HSV2 orally or genitally from partner who has HSV2, but if you and your partner both have the same type of HSV, you will not pass it to one another.
Herpes can be quite upsetting for some people, but it might help to know that it is VERY common, and that future outbreaks are usually less severe than the first one.
Let us know if you need more information,