No site says 6 months, thats been outdated since 2004.
HIV tests are now one the of the most reliable tests in the medical industry. You would not question a cancer test if you were negative would you? If your symptoms were HIV realted then you would have tested positive for sure. Whilst you may not be well, its nothing to do with HIV thats for sure so their is little point in beating a dead horse.
Even if you had HIV, any symptoms ( although HIV has NO specfic symptoms ) would have gone away by now, thats another reason to belive your test results