well i think lots of peeps have done it and i thought i would never do it myself
but....

yep, completely hooked by the green diesel sign at bp

tank was almost empty, just on the red, and put in about £3 before i realised....topped up with petrol afterwards to the click afterwards

car seems alright tho
should i panic?

do i feel dum,

 

Should be fine... Try not to abuse it too much, if you're worried.

The other way round is a lot worse.

PS: Your fuel pump and metering unit will love the additional lubrication Diesel provides...

 

Should be fine diluted as much as you have.