Nothing is as easy and forgiving to drive as a B44!
Did you set the slipper right, as I assume you will be running kit setup.
Too tight a slipper and it will be an animal in the wet.
I find that no roll bars / 10K oil all round / shock middle on tower / inner on wishbones (max droop) Kit pistons (40 oil front) (25 oil rear) and it works a treat. Never run greens though these days, Yellow's always or Balistic's if it's wet outdoors.
Think it may take you a while to get happy with it, something must be very wrong to go from 10/11 laps to 7. Maybe flog it to me and cut your losses