I have suffered from Lymphoma-HA for many years, so I appreciate what you're feeling right now.
Tightness and pain in the jaw, radiating down the neck is very likely muscular in nature. There are several very common causes for this; sitting in front of a computer or at a desk for long periods of time, neck strain from sleeping, poor posture, neck strain from exercise (eg: sit ups), stress and anxiety
, etc. The discomfort can really go on indefinitely until the underlying cause has been dealt with.
The glands located under the jawline and just under the ear can be felt in many people. I've always been able to feel mine, also more prominently on the right side.
Finally the itching you describe could really be anything from allergies to....zebras (I couldn't think of a condition starting with Z!)
Health Anxiety can make you very hyper-aware of everything going on with your body, so perhaps you always have the odd itch but subconsciously block it out!
You don't mention your age, but Lymphoma is a very rare disease, especially so in those under 50. I went to my old Doctor with my very first bout of Lymphoma HA, terrified because (of course) I "knew" I had it. I mean, I was completely convinced and had already mentally accepted the diagnosis before I'd even seen a Doctor. He was 79 years old at the time (!) and told me that in over 50 years of family practice he had NEVER seen a case of Lymphoma. That was a bit of a wake-up call for me and my HA, for sure. And of course after testing, all of my so-called "symptoms" turned out to be nothing.
It sounds like you do plan to visit a Doctor which is a good idea, but try not to worry in the mean time. I really think that you're fine, and have no cause for concern - certainly not about Lymphoma!