I don't think tinnitus is something that can spontaneously appear, I think it's something that develops over time. If the problem persists you should definitely talk to a doctor, but I don't think you really need to worry about this at uh, 20 years old. Also, before you assume this is tinnitus, I'm pretty sure there are a few illnesses that are similar to but not the same as tinnitus.
It can, it will develop over time if you're just constantly subject to high noises, listening to your ipod way too much etc, OR, you can get it immediately and permanently from things like a slap, gun fired close to your ear, or even an airplane flying close.
Also tinnitus heals more often than not (depending on what severity you would classify as tinnitus). If you're careful and stay away from high noises
and your goddamn ipod it can heal within the span of a year. If your condition has not improved in a year it is probably permanent.
A side note is you can get it even from low background noise if subject to it for a long time! If you work at a construction site, a factory, an airfield etc, wear ear mufflers. If you work in the music industry? you fucked son, 75% of people in the music industry have tinnitus.
Also Afura you most likely do not have tinnitus, it should go away in some days or weeks unless you have a perforated ear drum. Nevertheless you definitely should go to a doctor!