20 days ago in the evening I felt that my left arm pit was s...

Prompt

20 days ago in the evening I felt that my left arm pit was sore, like after I get it after a flu shot. In the morning I started feel like I'm coming down with a cold (feeling a bit under the weather) and my girlfriend reported that she started feeling sinus pressure and some sore throat. The next day, my armpit soreness improved and I got no other symptoms, while my gf started sniffling and got cold symptoms. 14 days ago, I was shaving with a razor and and cut myself in the neck several times. The next evening I started feeling sore left neck, like it was with an armpit. The next day, soreness reduced, I got no other symptoms. However after a 2-3 days, I started feeling some pressure in the left neck. I can feel like there some lymph nodes, but they seem like movable and not so big. And that feeling that something is there persist until this day. 5 days ago, I though it was getting better, because I doing other things and my attention was not on that spot. However, the next day it was pretty much the same sensation. The pressure that I feel is mostly now under the left jaw. Also, I feel sometimes a minor cloggy feeling in the left ear. Seems fine when I lay down and sleep, no discomfort. What it could be? I'm afraid of some type of cancer. Should I contact doctor asap? A few things that may or may not be important. I have no other symptoms I'm 30y old. No cancer history in the family. I have health anxiety. My previous cardiac "issues" resolved greatly, when doctor said that everything was fine. Almost 3 months ago, I have completed treatment for h.pylori (clari+amox+bismuth+ome) The last month my sleep was not great due to travelling, stress and heat waves, and bad sleep hygiene.