My fiancée said it was like my line was opened

Yesterday, I just wanted to get a trim, but the woman cut my hair however she liked, and now it's just above my shoulders. I've also noticed a lot of hair fall in the shower over the past few months, and it feels like the sparse spots have become even more obvious with the short hair. I looked in the mirror at night and cried, I won't lie. Today, my fiancé might not have meant it badly, but when he said it looks like my hairline has receded, I really felt down. On one hand, I want to go to the hairdresser to get extensions, but on the other hand, if this hair fall isn't normal, I'll just be covering it up for no reason. Has anyone else experienced sudden hair loss like this? Should I go straight to a dermatologist, or am I just experiencing haircut shock?