Dear Rahul, While guys wear condom after enjoying foreplay , few guys loose erection as wearing a condom distracts their mind temporarily from sexual excitement and due this disruption it is possible to loose erection. but if they continue sensual activity the will again get the firmness but if if they asses the penile rigidity it will go off, so is not a matter of health or lack of stamina . common cold
may affect your sex temporary as you are not feeling well. so don't bother be relaxed try to be more sensual towards your partner and don't observe your penile rigidity.