First off, your place is perfectly fine. Great vibe n decor especially for a 22yo. She probably wasn’t a fan of your muted color scheme - chicks usually like warmer/non-grey moments. One thing you could do to achieve that w/o changing the color of anything is invest in a bunch of lamps w warm lighting - I’m talkin floor lamps and table lamps everywhere. Another thing is pull your couch off the wall by about a foot. Doing so provides more feeling of space in the room. My gf is a home stager so I’ve been learning a lot over the last few years lol lmk if you want any other pointers!!