What Causes Dyspnea,fatigue And Dizziness?

hi,

I noticed that my right neck node (under the ear) is larger and more firm than the other, and also there is a rubbery, that is really firm. It's been this way for at least 4 months but it may even be as long as a year. Also I have other symptoms like dyspnea, fatigue, fever of unknown origin, extreme night sweats, pruritus and dizziness. I haven't done a blood test for over a year, maybe more. I also have tachycardia, but I have that for 2 or 3 years... I'm 19 years old, I study pharmacy, and I have no idea what can it be.. I haven't tell my parents yet, because they would tell me that this is nothing and I would be beter, so I wanted to have a doctors opinion first, so I could know what is going on... Please write back... Thanks a lot...