Audi A3 2001 Fuel gauge problem

Hello!

I just recently bought a Audi A3 2001 1.9 TDI Quattro, awesome car

Anyway, i recently got a little problem, it started with me driving with a friend on the road on 86mph-100mph (140km-160km). We had a little race and when we was done, i was going to park the Audi then suddenly i heard a pip, that it show it has little diesel. (was little fuel on before). But i said to myself that i would just wait to fuel it up, and just parked the car for 1 hour. After 1 hour, i drove to the fuel pump, and fueled for 30 usd, get in my car and twisted the key, but it continue to pip for low fuel....

So i drove abit, and parked, then i saw a period of 10-20min that the needle was danceing (moving to the point where it should be) but after that it just stayed on 0 fuel.

So anyone have any experience with this problem?
Would be really happy if someone could help me out.

Well, i dont know if that was the problem, but i feel maybe i pushed the car too much så cause the problem, or?

Thanks!

Will check if a friend got, but have searched on others forum abit, they say that it maybe be the sender who is dirty and need a clean