What are the risks of HIV infection for the passive partner of oral sex?

My question is about AIDS/HIV: I had a sexual affair that lasted two-and-a-half months, and, unfortunately, I was not using condoms. I happen to know nothing about my partner's previous sex life. I know that, for a test to show something, you must wait for six to nine months. I would like to know whether, provided that I am infected, I will experience any symptoms in this six to nine month period? Is it possible to have the virus and not have any symptoms or indications all this time? Right now, I am a graduate student and I am experiencing anxiety, fatigue, sleepiness, weight loss (three to five pounds in the last two months). Are these related to the disease, or is it just in my mind?

1) Can you get AIDS from a mosquito bite? I heard you can't, but I'm really paranoid about this. Actually, it wasn't a bite — I squashed the bug and all the blood in it splattered everywhere and then here I am with someone's blood on a cut in my finger. HELP! I'm really freaking out. I don't know if I should get tested or not again, because I did get tested before (negative), but the anguish of waiting for results was horrible. Maybe I'm just ultra paranoid?

2) Is it possible to contract AIDS by handling raw bloody meat?

What are the signs of an advanced case of syphilis, say twelve years down the road? Is treatment still possible or is it too late? I have reason to believe that I've been infected that long, and denying it. Would I still be contagious? Would I have been after five years?