Confused and Worried..Please Help!?

ok so im joing the military in 4 weeks and im alittle nervous...i went and had all my blood work by my doctor including Std's and HIV, and everything came back negative for std's and hiv and all other blood work was normal...my problem here is that i had sex with this girl i barely know maybe 3 weeks before the tests and the condom broke but we continued to have sex...everything was fine i felt fine and now maybe 2 months later i feel acky all over and im tired all the time even if i sleep 12 hours i still feel the need to take a nap during the day at some point,plus i have diarreh...Everyone is telling me im crazy for thinking i might have HIV because the most obvious symptoms that something is wrong is fever and swollen lymphnoids which i havent had at all...i went to the doctor yesterday and he checked my throat (physically and by sight) and nothing was there or wrong he said the only thing i had was post nasal drip and he said that i have a common cold or virus which is making me tired and all the muscle aches..but im scared out of my wits...i know i shouldnt worry cause i have proof i have nothing but i read that sometimes they come up false negative this and that..i also asked what test he used for hiv and he said it was a rapid test which i dont know what that is but he said its the earliest detecion one out there plus a western blot test and everything came back normal and not to worry but i been freaking out day in and day out over this which i know deep down is nothing but my mind has taken over and is telling me i have something...please help any way you can...thanks in advance..John A.