Swollen lymph node in neck I was told could be from infection in mouth. I don't want to go back because scared it's cancer?

Fear is the killer. Go back now...If it is just from infection than a round of antibiotics will take care of it. But if its cancer it will only get worse and grow larger and deeper. This makes it harder to cure. And we like to cure you.
Go back. Hopefully it is not cancer. But if it is, the earlier it is diagnosed, the better your chance for cure. Also - and importantly - the side effects of treatment are much worse for advanced head and neck cancer and the recurrence rate after treatment is much worse when it is advanced. If it is cancer - it won't go away and it will make you miserable without treatment. Get it checked!
Go back. Your doctor's impression is likely correct. Infection can and should be treated. Untreated infection can kill faster than a cancer.

Related Questions

I have multiple swollen lymph nodes in neck and back of head. They never get bigger their just there. Biggest one is 2.25 cm. Cancer?

Not Necessarily. I would see your doctor if this is the case. A variety of things can cause swollen lymph nodes and it is important to figure out if this could be something more serious.
Possible. Any lymph node larger than 2cm warrants further evaluation. However, the longer the nodes have been prominent but unchanged, the lower the probability of cancer. Other factors of importance include your age, smoking history, overall health, family history, etc. I advise you seek out a formal consultation from your primary care doctor. A biopsy may be indicated.

Swollen lymph node in neck? It moves around and its small im 16 and scared does it always mean something's wrong? Will I die? I feel fine

No. We all have lymph nodes and sometimes they will swell. The lymph nodes are part of your natural defense. They help remove infections and other substances from your body. They can swell in response to infection, or cancer, or nonspecific inflammation. I suspect yours is from a viral infection. Your physician can help clarify this for you.
Neck mass. Enlarged lymph nodes in the neck are very common and are usually benign. They may indicate infection or other things. The best is to show your doctor.

Have two swollen lymph nodes/lumps on my neck for years. No infections, possible cancer?

Most likely not. Probably not in a person as young as you if 1) they are not growing, 2) they have been stable for years, 3) you don't have symptoms of fever, weight loss, etc. But get them checked - lumps near the midline can be related to thyroglossal duct cysts and those on the sides may be branchial cleft cysts - both congenital abnormalities that should be treated.