Welcome to the STD forum. I'll try to help.
Most important, your positive HSV IgM blood test may be meaningless. It is inherently unreliable. Given your negative IgG test, there are two possibilities: first, you don't have HSV at all, and the IgM result is falsely positive; or second, you do have it and the IgG antibodies just haven't had time to become positive. Your symptoms were not typical for herpes, and my bet is on a false positive IgM test. Here is a thread that explains the IgM test in detail:
http://www.medhelp.org/posts/show/248394 Using the search link and entering "HSV IgM" will turn up hundreds of other discussions about it on this forum.
The lab rep you spoke to does not understand HSV antibody testing, and that misunderstanding is reflected in some of your questions. There is no such thing as being exposed but not infected. If the HSV antibody test is positive, the person has not only been exposed but is infected and continues to carry the virus.
To your specific questions:
1) Apparently there are no HSV antibodies "in your system". But please report the details of your IgG test result. You also should plan on another IgG test about 6 weeks after the sexual exposure. That's the one that will tell for sure whether or not you were infected.
2) If you are infected, you will not "fight it off". All HSV infections are permanent and lifelong.
3) Sometimes it takes 3 months (90 days), but most people with new HSV-2 have positive results by 6 weeks. If a 6 week test remains negative, a final test at 3-4 months is recommended.
4) If you caught HSV and then had sex while still having symptoms of the initial infection, you definitely could have transmitted it to that sex partner. But I stress that my best guess is that you were not infected, so probably there was no herpes for you to transmit.
5) Viraway, Immune Builder, and other "immune system boosters" are quackery that will have no effect. Don't waste your money. Anyway, even when real anti-herpes drugs like acyclovir are administered as soon as 1 hour after exposure, they do not prevent establishment of HSV infection. I'm afraid in your case the horse is well out of the barn and galloping over distant fields, so no point in closing the barn door now. You are infected or you are not, and at this point you can't do anything about that.
But don't be discouraged. The odds are you weren't infected with herpes; and if you were, with proper management genital herpes need not be such a big deal.
Bottom lines: Let me know your recent HSV IgG test results, and plan on another test in about 3 weeks. In the meantime, try to stay mellow. Most likely your IgM was falsely positive and you don't have it.
Best wishes-- HHH, MD