Worried about a neck lump

I'll keep it short but basically I'm quite worried about a hard lump on the left hand side of my neck.

 

it's been there for 4 months now and to be honest I've grown used to it, however I am a bit concerned after googling what it could be.

 

I haven't felt ill once besides having a sore throat every now end then and I'm worried that it's something sinister. I'm only 20 and I'm at uni, so I'm very stressed as you can imagine.

 

Any other experiences would be great to hear about as I'm very worried. Thanks.