I've been smoking for 5 months, i recently developed a pain in the neck, and throat infection, could it be a cancer within such short duration of smok?

Unlikely: It is not a question that can be answered well on this format, but it is doubtful that the contact with smoking for 5 months would lead to cancer. If you developed a throat infection, it is likely that the smoking had something to do with the presentation - smokers are more likely to get ill, develop pneumonia or complications of upper respiratory tract infections. Good luck - great time to quit