What caloric deficit do you use?

[Mo T 4 Me]

I have been dieting since several week, eating about 1800 cal a day (40G/40P/20L). I'm 5 7, 155lbs, 9% bodyfat.
I think my caloric deficit is at least 500cal with this diet but I feel like I dont lose fat.

I dont really know what to do. Lowering cal would be psychologically very hard.

Should I make more cardio? I'm doing 20 min everyday but i'm afraid of losing muscle since I dont use any chemical.