Welcome to the HIV forum.
Symptoms almost never are useful clues about new HIV infections. Your wife's symptoms do not sound like those of an acute HIV infection, but even if they did, the odds would be against it; even classical acute HIV symptoms usually are caused by other, more common viral infections. Further, it is pretty much impossible that you caught HIV, transmitted it to your wife, and she developed symptoms all within 2 months since your last negative test. Further, most sex workers -- including those in India (if your username means you live there) -- do not have HIV. Finally, it is exceedingly unlikely you could have acquired HIV despite consistent condom use for your non-marital sexual exposures.
By far the greatest likelihood -- by odds of thousands to one -- is that your wife just caught a garden variety gastrointestinal virus. Assuming her symptoms continue to clear up, I really wouldn't worry about it. Of course if you remain concerned you can always have another HIV test to help prove to yourself you haven't been infected. And of course if your test remains negative, it is impossible you infected your wife.
And by the way, I have no patience with "I do not have the courage to test" for HIV. It isn't the test that makes someone infected; and research shows that when someone is frightened of testing and finally does it, even if the result is positive, anxiety declines -- i.e. learning of a positive result is less stressful than the worry about it. As I said above, I truly believe you do not need to be tested -- but if you remain concerned despite my reassurance, just do it. It will be negative.
In the meantime, don't worry about it. Your wife's illness has nothing to do with your extramarital sex.
Regards-- HHH, MD
Thanks a lot, it is helpful indeed.