Last night my boyfriend (35, non smoker, fit and healthy) found a lump in his neck. It's on the left side, half way between his ear lobe and collarbone. It's not visible, it feels deep, but hard and painless. He has lost weight over the last month, but has recently taking up cycling- which could offer the explanation. He also has mild night sweats, however he has always had these. 
 

He saw the GP this morning, who said it feels very large and is concerning. He sent him for urgent bloods. He is now on a 2WW to see ENT and I am so worried. I can't stop crying, and thinking the worst. I'm trying to be strong, but I'm a health professional myself and sometimes knowledge definitely isn't power. 

He did recently have viral gastroenteritis but I don't know if this could cause a reactive node?

I can't stop thinking about lymphoma or lukaemia. I'm so sick with anxiety. I don't know what to do.