I personally would kick off if my friend had it and didnt tell me - that truly is NOT a truthful friend you have there.
Question - so once you get it, that's it? its in your immune system for good???
OP: try not to stress too much. Definately cant be easy for you but im sure it'll get better soon. Try to not get too paranoid. Talk to close family or friend who is able to understand your problem.
Hope that makes sense and helps.