Please take a deep breath and relax, my friend. That pea sized lumb on the right, dorsal aspect of your neck is most probably a post-auricular lymph node. Usually a "skin lesion," that is, a simple scratch to the skin on the scalp (in your case on the right side) or a infection (like a pimple (carbuncle)) or some other source of infection is the cause. We do not want to think, or quickly expect, that the problem is a cancer. My advice to you is to have someone (I know that it cost money to go in to see a doctor) but I really want to know, for your "peace of mind" and for my sake, that the problem is a simple thing that can be cleared up quickly and easily. I feel that it is a simple, localized infection of the skin over your right, posterior scalp that can be cleared up very easily if you go in to a doctor to get the proper diagnosis and some medication.
I which that I, personally, could see you, examine your scalp, and then treat the problem, but I am retired from clinical medicine, after working in the medical field for 20 years, so I really should be advising you to see someone else. I want to know how you are doing however. I am a friend to all you are in need and have a problem.
By the way, it is good that you have stopped smoking, because a beautiful young lady like yourself have a longer, healthier life ahead of her if she does not smoke.
Let me know how things turn out. My prayers are with you. My friendship is with you and you are not facing this problem by yourself.
If you want to write me more, it's okay. Take care.
Joy, Peace, and Hope,