Just stating the obvious...a Mediterranean diet is high in olive oil and other omega 3s. You might need to balance your omega 3-6 ratio by consuming less vegetable oil which is hidden in many foods. Here's some things you should do:
Eating primarily plant-based foods, such as fruits and vegetables, whole grains, legumes and nuts
Replacing butter with healthy fats, such as olive oil
Using herbs and spices instead of salt to flavor foods
Limiting red meat to no more than a few times a month
Eating fish and poultry at least twice a week (make sure it's wild caught fish, preferably salmon)
Drinking red wine in moderation (optional)
I think the Mediterranean diet you were eating was anti-inflammatory and was protecting you from acne. If you balance your omega 3-6 ratio your skin will return to normal.