i recently having dry mouth.. and googling dymouth found out that it might be due to HIV.. and also found my tongue has slight white coating..googling that found out it might be oral thrush

I started having sex with my wife from feb month..i had protected sex with her for a month in March...she had a blackened rash or on her hand...this is for the first she had witnessed cold winter ( US midwest winter dryness) . she didnot have any flu like symptoms like fever or cold or any lymp nodes.

from past 2 weeks i am being paranoid about HIV.... 

Do you think i might have HIV.

Welcome to the Forum and thanks for your confidence in our service.  I hope that my reply will relieve your concerns.  The encounter that you describe was a virtually no risk event.  Most commercial sex workers do not have HIV. even if your partner was infected, the probability of infection from a single unprotected exposure (yours was protected) is less than 1 infection per 1200 sex acts, and with condom worn throughout sex that does not break, your risk for infection is reduced nearly another 1000-fold, making the exposure virtually no risk.  you can have confidence in your condoms as well since on those rare occasions when condoms do fail, they break wide open leaving no doubt that they failed.

Google is not your friend here.  Dry mouth is not a typical sign of HIV and is very, very non-specific. Similarly, a white coating on your tongue is more likely to be due to your dry mouth than thrush which is much more obvious.

If my reassurances do not resolve your doubts, I suggest you get a single test for HIV at this time.  this long after exposure your results will be entirely reliable and, I am confident, will be negative.  

I hope that this information is helpful.  EWH

I studied about HIV phases... since its been 7yrs since i had the encounter.. do people have 2nd stage of HIV  for these many years.  

No, thrush looks nothing like this.  It is far whiter, thick and is typically present on the roof of the mouth and/or back of the throat as well as on the tongue.

I'm not sure what you mean by 2nd phase of HIV.  Typically, once persons are beyond their initial symptoms in the month or so following infection, most persons are asymptomatic until they begin to experience the opportunistic infections which are used to define AIDs.

Please don't worry. EWH