Glandular fever is very nasty. A couple of people in my halls got it last year, and they had to go home for ages. It can last for a really long time, and so it's unwise to try and treat it yourself. I think you'd have more symptoms if it really was glandular fever tbh, rather than just a lump.
Is the lump on just one side? Could be mumps. Any aching on that side of your face? When I got mumps the lump and swelling appeared a few days before the pain, but believe me, if it comes, you'll damn well know about it.
I went to the doctor a few days ago because of a mild sore throat that wasn't shifting, coupled with a lump around my glands and apparently I have tonsillitus.