Advice Please Whether to Contact Buyer? How to Proceed with Big Sale?

I had a sale today for a designer perfume where the buyer paid over $400 with tax & shipping. Buyer has 3 FB and joined in December. eBay says it will be delivered between Feb. 12 and Feb 14. Eek! Perfumes can only be shipped Ground Advantage which will likely take 7 - 10 days.

I went back to listing and saw it was my mistake listed as Priority Mail. I find the "shipping policy" section on Seller Hub confusing, depending on what I'm selling, and I messed up.

Should I proceed to pack & ship this sale, or should I contact the buyer first, explaining it can only be sent by Ground Advantage that's going to take much longer?

If the person wants it for Valentine's Day this Friday, they will be disappointed or angry. How do I handle this situation?