Am I the process of being scammed ?

Hi everyone, recently I decided to try and "trade" with someone on vinted. Basically they sold me a shirt for a pound and I sold my T-shirt for a pound as well. Thing is, this buyer does not have stellar reviews and I'm afraid he will cancel the order and keep the shirt I sold or maybe send me an empty package and just accept my order. I only just now realized that this might be a scam as obvious as it may seem. Has this ever happened to anyone any advice on what I can do now ? My shirt hasn't sold yet so maybe I could just cancel the order I made.