Add olive oil and garlic, and let cook for 1 minute.
Add shrimp, butter, Italian seasoning, and lemon juice, and cook for 1 min., then add lemon zest, olives, Feta, and cream cheese, and let simmer for 2 more minutes or until cream cheese melts into the sauce and the shrimp are pink, and cooked through.
Add salt and pepper to taste, and mix well.
Plate spaghetti on a pretty serving dish, then spoon sauce and shrimp over pasta.