I made an appointment for breast augmentation but I can't decide on the size.

My ribcage is about 65 cm right now and my cup size is AA cup,
 but I'm getting breast surgery soon and I decided to get Mentor Extra implants. I just need to decide on the cc size, but since I like big breasts, I'd like at least a full C to D, so the director said that I need to get between 375 cc and 415 cc in high-low...ㅠㅠ But if I go high-low, it'll look too rocket chest and be very unnatural and weird, so I said I'll go with 350 cc for now, but my body produces about a C to full C in 350 cc, but if I go with 350 cc, I'm really worried that I'll be dissatisfied because the size is too small...ㅠㅠ These days, when I look at YouTubers or BJs, their breasts are naturally big. I want to get that size, but I don't want them to be too unnatural... Am I being too greedy?? I've been worrying about this for weeks and it's giving me a headache. Please give me some advice...ㅠㅠ