I don't know if I'm just stressing over nothing and I am going to see the GP this week but I'm worried they won't take me seriously - I'm 18 and I think i have symptoms of Hodgkins lymphoma

About a week ago after a hangover i got a hard lymph node on my neck that is only a bit achey/tender when I touch it but otherwise painless and has grown slightly, the lump itself is solid but moves when touched. I haven't been ill recently, only a slightly dry throat when I swallow, but then I also noticed I can feel the lymph node behind my knee, my scalp has been a bit itchy, and my legs feel unusually weak - especially going up stairs they feel really heavy and I have lost appetite a bit. 

I don't know if half these symptoms are just from the stress of thinking I have it but I'm worried the GP will just tell me to wait a bit for it to go down but I am such a control freak and it's already all I can think about. I know i shouldn't trust google too much but if anyone has any advice on how to get your GP to get you tested or any similar symptoms or possible explanations let me know!