Anxious about lymph node - advice?

So ever since a over year ago (April) I have had chronic health issues. I am only 18, however I found this quite worrying, as I randomly fell ill for no reason. I felt winded, wiped out, had enlarged lymph nodes, everything. They all went away, and were fine. However I'd actually noticed i had one for a long time anyways on my jaw. this one has disappeared as far as i can feel. however one has just never left and has been there for ages as i can remember. Well, recently I've been feeling like its a bit harder and a tiny bit bigger. Its on my jaw above the bone on the right side, kind of diagonal to my ear. it is not huge, however i am still worried about it. I've had fatigue and stuff for over a year, including shortness of breath and arrhythmia. I have also had really bad anxiety and panic disorder. However this entire time I'd had tests including blood many times and everything was perfect apparently. A few weeks ago I had a severe asthma attack and heart rate was high so went to doctors, then A&E. this literally happened out of nowhere. they did an ecg and said it was okay and came back down, blood showed slightly high white markers at 15. i had this test repeated a few days ago and its back down to 11, and all my other CBC is fine. the GP said they had tested me for blood cancers (which they nicely never informed me about) and they were fine, so I 'didnt have to worry'

 But since I've remembered this node being there, I decided to google what it could be, and as you imagine, I was terrified to see the results. Instant panic. I had a chest x ray in A&E after they said I had a fever (unexplained) and they said my chest x ray was perfectly fine. I asked the doctor in A&E about the lump and the Nurse Practitioner and they both said 'well if its not growing rapidly and isn't painful don't worry, lots of people have cysts' but it still didnt feel right to me. I asked if I could ask my GP to look at it and he said he didn't see a need. So, I returned home.

GP refused to even feel it at a face to face consultation or refer me anywhere because 'I was young' even though lymphoma is one of the most common in my age group. They said because it wasn't a blood cancer they weren't worried??? then they basically told me they wouldn't help me because of my anxiety, which ended in me crying and walking out. I then have contacted my other GP and told him about this. He said because the CBC is okay and that my chest x ray is fine it is not likely at all my gastrointestinal issues are related, but my referral for an abdominal CT scan is still being made fairly soon, and endoscopy (I had blood in my stool and constipation recently, extreme acid reflux for a while and stomach ache referring into diaphragm) 

Then he moved onto the lump, i mentioned the lump and how i couldn't tell if it was getting bigger. i also told him i recently have been sweating more and more (not at night really, mostly during the day) and that I felt tired and kept waking up. I stopped my anti depressants because I thought this could be the cause, however I am unsure. 

The lymph node is only one as far as feelable, they felt my neck and said it was all fine, and the node is not that big at all really. it isn't painful, is quite firm but does move a bit? if I roll it across my finger it kinda makes a clicking noise? 

The other GP has asked to urgently see it face to face and sounded a bit concerned, so I'm quite worried.

has anyone else had similar experiences and if so what are your outcomes? what tests dis you have? and if I had a clear chest x ray and other tests (stool, urine, blood etc) would it likely to have spread if it was lymphoma? or would that not show, because google gives very mixed info :| 

and if anyone did have lymphoma of any kind, what kind of treatment did you have and was it successful?

Thanks, Kaia