There's really no preventative measures to be taken here because you two are not going to ping pong the infection back and forth. It's always wise to not perform or receive oral sex when you or your partner has an obvious cold sore just to be cautions. Here's a thread I'd like you to read regarding spreading the infection between two partners with the same strand of HSV-1.
http://www.medhelp.org/posts/STDs/Partners-have-different-HSV1-genital--oral-/show/1129351
The cold sores you got are from his mouth, not his genitals. Cold sores are spread through romantic kissing, and it's highly, highly unlikely you got this from performing oral sex on him. To answer your first question, no, he has cold sores, and not genital herpes. There's really no possibility that he has genital herpes because (a) you're the first one to perform oral sex on him (he already has oral HSV-1), and (b) he's a virgin, which eliminates HSV-2.
Once you got your oral herpes from your boyfriend, your body started creating antibodies, which prevent the virus from being spread to other locations and fights the virus. In almost all cases, if not all, after the primary outbreak, you cannot spread HSV-1 to other parts of your body. Since your oral herpes came from his oral herpes, you have the same strain, which means you won't be infecting each other at other locations. To be cautious, I would give the antibodies some time to develop since this is a new infection, and refrain from receiving unprotected oral sex for 3-6 months...That's being really cautious. Until some time passes, you can use dental dams or saran wrap while he performs oral sex on you.
You can still perform oral sex on your boyfriend without worry due to his oral herpes being a longstanding infection. His body has had time to develop antibodies that will prevent it from being transmitted to another location on his body. He is immune from catching it on another part of his body. The fact that you have the same strand since it was given to you by him makes the immunity of catching the same virus in another location even more reassuring.