If you have a vaginal odor, go see the doctor and ask to get swabbed for BV. You don't have to tell him *how* you think you got it (besides, it's even possible the timing was a coincidence and you didn't get whatever you have from your hairbrush). Just tell him you think you have a vaginal infection of some kind. BV's hallmark is a peculiar odor, someone googling "vaginal odor" would find it, you going to a doc after looking it up is not going to surprise the doc. And it's serious (not the BV itself, but what can happen if it's left untreated). Lots of women will definitely take themselves to the doc for a vaginal infection, especially if it seems like it might be BV. The doctor will do a swab test, and if you do come up positive, it takes a run of antibiotics to make it go away (it's not anything you can douche away).
I'm sorry you took specialmom's advice about being careful of what you send online as somehow insulting. So what if others put sex-toy films out on the Internet and this is comparatively not as blatant. This is you and your life we're talking about, not others. Having things like this in the ether is a risk. Even if your boyfriend is perfect and never, ever shows this to a buddy, there is always hacking, or a snoopy roommate or some future girlfriend finding it and putting it out there for people to see because who are you to those people? Please be safe. If you feel like doing this is a condition of your relationship, it probably isn't. But if your boyfriend asks you to do this (or even just to send nudes online), given how insecure people's supposedly private online communications are, he is not being very protective of you.
Ugh. Well, obviously a hair brush is nothing like a penis. Not a great masturbation tool and doing this on web cam . . . I know you trust your boyfriend . . . but this is just something that could come back to bite you. I know a guy who saved everything, recorded everything . . . that sexy and fun photo session with his ex girlfriend? became a party joke that he showed everyone.
Anyway, I have no idea what is going on. Smells from the vagina and itching are indicative of something. Bad odors are often an infection. I think you may just have to go to the doctor and deal with it. They see and hear a lot of things, so they will not be shocked. But agree it is a little embarrassing. but your health comes first. good luck