Oral Head and Neck Cancer Information and Support

I am literally obsessing over my health right now. A few months ago I was in the shower and was rubbing my neck (which has been giving me issues for MONTHS) and noticed a very large hard lump on the right side. When I jumped out of the shower and looked in the mirror you could clearly see if from the outside of my skin. The lump is very hard and seems to be getting bigger. There is certainly some tenderness when I touch on it but it is not painful, just more of a discomfort. I went to the Dr. who told me it was a swollen lymph node. I had NO other symptoms at this time of a cold or anything of that sort. He prescribed me an antibiotic for my mysterious condition which I know I did not have. Mind you he didn't even touch or feel my neck. What a quack! So fast forward a few weeks and the lump is still there, hard, solid and driving me insane.
So last week I saw online a Groupon for a cheap chiropractic massage. I said what the heck why not, maybe this will help relieve some of my neck pain. So I went to the chiropractor and he took x-rays of my neck but couldn't really tell me too much from what he saw because it wasn't a formal appointment. In the x-ray you can CLEARLY see a large mass on the outside of my neck. I am literally freaking out. I have 2 young girls, I am recently single raising them alone. I don't know what to do. I made an appointment for Friday with a different Doctor in my practice to get a second opinion and I refuse to leave without answers. I am just not sure what this could be. It doesn't seem like a swollen lymph node. I am not really experiencing other symptoms as of now. A slight cough due to the cold circulating around my family, constant headaches that persist throughout the whole day (catscan of head came back clean) and achy shoulders and neck.
Does anyone have ANY insight. I just need to calm myself down before Friday. I am constantly crying literally obsessing over this. I just want to be ok

Help!