Weird sickness

I'm slightly sick but I've never experienced this before.

So, on Saturday I woke up feeling nauseous, threw up a few times before going to work. Worked a full day, felt nauseous for some of it. Had many moments of feeling extremely strange, kind of feverish. In one class I thought I was going to faint.
Felt totally normal Sunday and Monday.

Tuesday, I mostly felt normal but this evening started getting some weird symptoms again and again with the dizziness/nausea and strange feelings.

By strange feelings, I mean... well, you know when you have a fever, and you think in a strange way? For example, you get one particular thought or idea stuck in your head, and you can't get it out? Or you remember - or think you remember - some long-forgotten event or story you once read, and it seems incredibly important and profound, and yet you had no memory of it before you got the fever?

On Saturday the weird thing was deja vu. I had indeed taught all those lessons before, but I felt extremely acute deja vu. I actually felt as if I had already experienced everything on that day - I heard the exact same questions, I replied using exactly the same words, we went onto exactly the same tangents, students made exactly the same points. Even when I talked to a staff member about a student report, I felt as if we'd had an identical discussion - right down to the exact sentences we were using - a few weeks earlier.

Apart from sudden attacks of nausea and dizziness, which have never lasted more than a few minutes, I've felt fine apart from moments of slight headache or sore throat. Today I again had a couple of moments of panic where I felt so dizzy that I wondered if I was going to throw up or have to lie down on the street.

Any thoughts on this? I'd peg it down to some kind of weird virus and a touch of fever, but it seems very strange to me that I should feel totally fine on the weekend and then sick before and after it. Right now I feel pretty normal except for a very slight headache.

I had an awesome weekend, incidentally. I must post about it soon. ^_^