Just race normally on race B next week and you'll be reset. Race B will only be worth 6 SR at most, one SR Down is -10 SR. There's only one way for SR to go. You can help it along by turning around, drive until the dq timer shows up, turn around, drive until SR Down pops up, repeat. However that SR Down is only worth -2 points (unless changed again), so you need to do it 47 times and quit at the last moment for an extra -5 SR.
N300 again, always slow cars on the Nord. One lap from the back, it will never be boring at least.
N100 and GR.4 for the other choices. It will feel like crawling after 373 kph all week.
One advantage of race B, less of a wait when "disconnected due to data loss" pops up again

Grr, was 5 sec behind the leader start of lap 2, would have been an easy victory.