petrol in my diesel tank

drain the fuel tank, replace the fuel filter fill up with diesel, should run fine again

damage that could have been done is that the fuel pump was not lubricated for a while but bosch pump are quite rugged and can stand a fair amount of abuse

oh and yes you are plain stupid, as s my mom and half of my friends....( the other half drives petrol)

So many people have done this, so don't worry. How much was in the tank before this incident? If it was quite low, then you will only have put in max 1/4 of a tank. You need to fill it up with diesel ASAP, but you could add a couple of bottles of veggie oil to increase the lubricating quality of the fuel. Then as suggested, drain the filter and pump up new fuel until you lose the neat petrol. Then bleed as usual and it should restart OK and all will be fine. I doubt you will ever do it again :)